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756 Maths In Focus Mathematics Extension 1 Preliminary Course
Answers Chapter 1: Basic arithmetic
Problem
5
Exercises 1.1
1. (a) Rational (b) Rational (c) Rational (d) Irrational (e) Rational (f) Irrational (g) Irrational (h) Rational (i) Rational (j) Irrational
2. (a) 18 (b) 11 (c) 6 (d) 11 (e) .4 3- (f) −1 (g) 2157
(h) 12019
(i) 2 (j) 331
3. (a) 16.36 (b) 21.87 (c) 8.80 (d) 22.71 (e) .13 20-
(f) 0.17 (g) 0.36 (h) 1.20 (i) .4 27- (j) 8.16
4. 1300 5. 950 6. 3000 7. 11 000
8. 600 9. $8 000 000 10. $34 600 000
11. 844 km 12. 0.73 13. 33 14. 3.248 15. 4.21
16. 1.7 17. 79 cents 18. 2.73 19. 1.1 20. 3.6 m
21. $281.93 22. 1.8 g 23. $3.20
24. (a) 7.95 (b) 30.03 (c) 0.37 (d) 5.74 (e) 0.52 25. 0.2
Exercises 1.2
1. 1 2. 11- 3. 56- 4. 10 5. 4-
6. .1 2- 7. .7 51- 8. .35 52- 9. 6.57
10. 2154
- 11. 7- 12. −23 13. 10 14. 1
15. 5 16. 3 17. 1 18. 60 19. −20 20. 9
Exercises 1.3
1. (a) 2516
(b) 100051
(c) 5201
(d) 1154
2. (a) 0.4 (b) 1.875 (c) .0 416o (d) .0 63oo
3. (a) 501
(b) 83
(c) 1000
1 (d) 1
100097
4. (a) 0.27 (b) 1.09 (c) 0.003 (d) 0.0623
5. (a) 35% (b) %3331
(c) %22632
(d) 0.1%
6. (a) 124% (b) 70% (c) 40.5% (d) 127.94%
7. (a) . ;0 522513
(b) . ;0 071007
(c) . ;0 16812521
(d) . ;1 09 11009
(e) . ;0 434500217
(f) . ;0 122540049
8. (a) .0 83o (b) .0 07oo (c) .0 13oo (d) .0 16o (e) .0 6o (f) .0 15oo
(g) .0 142857o o or 0.142857 (h) .1 18oo
9. (a) 98
(b) 92
(c) 195
(d) 397
(e) 9967
(f) 116
(g) 457
(h) 6013
(i) 990217
(j) 149537
10. (a) .0 5o (b) 7.4 (c) 0.73o (d) .0 68oo (e) .1 72oo
11. (a) 85
(b) 281
(c) 118
(d) 2187
(e) 454
12. 74% 13. 77.5% 14. 17.5% 15. 41.7%
Exercises 1.4
1. 203
2. 207
3. (a) 2017
(b) 107
(c) 1201
(d) 283
(e) 53
4. $547.56 5. 714.3 g 6. 247
7. $65
8. 179 cm 9. (a) 11.9 (b) 5.3 (c) 19 (d) 3.2 (e) 3.5 (f) 0.24 (g) 0.000 18 (h) 5720 (i) 0.0874 (j) 0.376
10. $52.50 11. 54.925 mL 12. 1152.125 g 13. $10.71
14. 5.9% 15. 402.5 g 16. 41.175 m 17. $30.92
18. 3.2 m 19. 573 20. $2898
Problem
5115 minutes after 1 o’clock.
Exercises 1.5
1. (a) 500 (b) 145 (c) 641
(d) 3 (e) 2
2. (a) 13.7 (b) 1.1 (c) 0.8 (d) 2.7 (e) .2 6- (f) 0.5
3. (a) a17 (b) y 10 = (c) a 4- (d) w (e) x5 (f) p10
(g) y6 (h) x21 (i) x4 10 (j) y81 8- (k) a (l) y
x45
10
(m) w10 (n) p5 (o) x 3- (p) a ba
bor2 3
2
3-
(q) x yx
yor5 2
5
2
-
4. (a) x 14 (b) a 7- (c) m 4 (d) k 10 (e) a 8- (f) x (g) mn 2
(h) p 1- (i) 9 x 22 (j) x 21
5. (a) p 5 q 15 (b) b
a8
8
(c) b
a6412
3
(d) 49 a 10 b 2 (e) 8 m 17
(f) x 4 y 10 (g) k27
2 23
(h) 16 y 47 (i) a 3 (j) x y125 21 18-
Answer S1-S5.indd 756 7/11/09 1:26:16 AM
757ANSWERS
6. 421
7. 324 8. 22710
9. (a) a 3 b (b) 251
10. (a) pq 2 r 2 (b) 327
11. 94
12. 181
13. 274
14. 811
15. 108
1 16.
121
17. 2
558
22
18. 388849
Exercises 1.6
1. (a) 271
(b) 41
(c) 3431
(d) 10 000
1 (e)
2561
(f) 1
(g) 321
(h) 811
(i) 71
(j) 811
(k) 641
(l) 91
(m) 1
(n) 361
(o) 125
1 (p)
100 0001
(q) 1281
(r) 1
(s) 641
(t) 641
2. (a) 1 (b) 16 (c) 121
(d) 12511
(e) 1 (f) 125 (g) 131
(h) 49 (i) 383
(j) 32 (k) 231
(l) 1 (m) 13613
(n) 18119
(o) 1 (p) 16 (q) 1585
- (r) 237
- (s) 1 (t) 2516
3. (a) m 3- (b) x 1- (c) p 7- (d) d −9 (e) d −5 (f) x 2-
(g) 2x 4- (h) 3 y −2 (i) 21
z 6- or 2
z 6-
(j) 5
3t 8-
(k) 7
2x 1-
(l) 2
5m 6-
(m) 3
2y 7-
(n) 3 4x 2+ -] g (o) a b 8+ -] g
(p) 2x 1- -] g (q) 5 1p 3+ -^ h (r) 2 4 9t 5- -] g
(s) 41x 11+ -] g
(t) 9
5 3a b 7+ -] g
4. (a) 1
t5 (b)
1
x6 (c)
1
y3 (d)
1
n8 (e)
1
w10 (f)
2x (g)
3
m4
(h) 5
x7 (i)
8
1
x3 (j)
41n
(k) 1
1
x 6+] g (l) 8
1y z+
(m) 3
1
k 2-] g ( n) 3 2
1
x y 9+^ h (o) x 5 (p) y 10 (q) 2
p
(r) a b 2+] g (s) x y
x y
+
- (t)
2
3
w z
x y 7
-
+e o
Exercises 1.7
1. (a) 9 (b) 3 (c) 4 (d) 2 (e) 7 (f) 10 (g) 2 (h) 8 (i) 4 (j) 1 (k) 3 (l) 2 (m) 0 (n) 5 (o) 7 (p) 2
(q) 4 (r) 27 (s) 21
(t) 161
2. (a) 2.19 (b) 2.60 (c) 1.53 (d) 0.60 (e) 0.90 (f) 0.29
3. (a) y3 (b) y yor23 32_ i (c)
1
x (d) 2 5x +
(e) 3 1
1
x - (f) 6q r3 + (g)
x x7
1
7
1or
25 5 2+ +] ^g h
4. (a) 2t1
(b) 5y1
(c) 2x3
(d) x9 31
-] g (e) 2s4 1+1] g
(f) 2t2 3+-
1] g (g) -
2x y5 -
3^ h (h) 2x3 1+5] g
(i) 3x 2--
2] g (j) 2y21
7+-
1^ h (k) -
3x5 4+1] g
(l) y32 1 2
1
--
2a k (m) x53 2 4
3
+-
2_ i
5. (a) x 23
(b) x 21
-
(c) x 32
(d) x 35
(e) x 45
6. (a) x x x2 23
+ +2 (b) a b32
32
- (c) p p p2 21
+ +1-2
(d) 2x x 1+ +- (e) x x x321
23
25
- +- - -
7. (a) 2
1
a b3 - (b)
3
1
y 23 -^ h (c) 6 1
4
a 47 +] g
(d) 3
1
x y 54 +^ h (e) 7 3 8
6
x 29 +] g
Exercises 1.8
1. (a) .3 8 103# (b) .1 23 106
# (c) .6 19 104#
(d) 1.2 107# (e) .8 67 109
# (f) .4 16 105#
(g) 9 102# (h) .1 376 104
# (i) 2 107# (j) 8 104
#
2. (a) .5 7 10 2#
- (b) .5 5 10 5#
- (c) 4 10 3#
-
(d) 6.2 10 4#
- (e) 2 10 6#
- (f) 8 10 8#
-
(g) 7.6 10 6#
- (h) 2.3 10 1#
- (i) 8.5 10 3#
- (j) 7 10 11#
-
3. (a) 36 000 (b) 27 800 000 (c) 9 250 (d) 6 330 000 (e) 400 000 (f) 0.072 3 (g) 0.000 097 (h) 0.000 000 038 (i) 0.000 007 (j) 0.000 5
4. (a) 240 000 (b) 9 200 000 (c) 11 000 (d) 0.36 (e) 1.3 (f) 9.0 (g) 16 (h) 320 (i) 2900 (j) 9.1
5. (a) 6.61 (b) 0.686 (c) 8.25 (d) 1.30
6. 1.305 1010# 7. 6.51 10 10
#-
Exercises 1.9
1. (a) 7 (b) 5 (c) 6 (d) 0 (e) 2 (f) 11 (g) 6 (h) 24 (i) 25 (j) 125 2. (a) 5 (b) −1 (c) 2 (d) 14 (e) 4 (f) −67 (g) 7 (h) 12 (i) −6 (j) 10 3. (a) 3 (b) 3 (c) 1 (d) 3 (e) 1 4. (a) a (b) a- (c) 0 (d) 3 a (e) −3 a (f) 0 (g) 1a + (h) a 1- - (i) 2x - (j) 2 x-
5. (a) | | 6a b+ = | | | |a b 6+ = | | | | | |a b a b` #+ + (b) | | 3a b+ = | | | |a b 3+ = | | | | | |a b a b` #+ + (c) | | 1a b+ = | | | |a b 5+ = | | | | | |a b a b` #+ + (d) | | 1a b+ = | | | |a b 9+ = | | | | | |a b a b` #+ + (e) | |a b 10+ = | | | |a b 10+ = | | | | | |a b a b` #+ +
6. (a) | | 5x x2 = = (b) | | 2x x2 = = (c) | | 3x x2 = =
(d) | | 4x x2 = = (e) | | 9x x2 = =
7. (a) x x x x5 5 5 5for and for2 1+ - - - - (b) b b b x3 3 3 3for and for2 1- - (c) a a a a4 4 4 4for and for2 1+ - - - - (d) y y y y2 6 3 6 2 3for and for2 1- - (e) 3 9 3 3 9 3x x x xfor and for2 1+ - - - - (f) 4 4 4 4x x x xfor and for1 2- -
(g) 2 1 2 1k k k k21
21
for and for2 1+ - - - -
(h) 5 2 5 2x x x x52
52
for and for2 1- - +
(i) a b a b a b a bfor and for2 1+ - - - - (j) p q p q q p p qfor and for2 1- -
8. x 3!= 9. 1! 10. , x1 2! !
Answer S1-S5.indd 757 7/11/09 1:26:17 AM
758 Maths In Focus Mathematics Extension 1 Preliminary Course
Test yourself 1
1. (a) 209
(b) 0.14 (c) 0.625 (d) 200157
(e) 1.2%
(f) 73.3% 2. (a) 491
(b) 51
(c) 31
3. (a) 8.83 (b) 1.55 (c) 1.12 (d) 342 (e) 0.303 4. (a) 1
(b) 1 (c) 39 (d) 2 (e) 10- (f) 1- (g) 4 5. (a) x9
(b) 25y6 (c) a b11 6 (d) 27
8x18
(e) 1 6. (a) 4029
(b) 371
(c) 12 (d) 221
(e) 1221
7. (a) 4 (b) 6 (c) 19
(d) 641
(e) 4 (f) 3 (g) 71
(h) 2 (i) 1 (j) 4
8. (a) a 5 (b) x 30 y 18 (c) p 9 (d) 16 b 36 (e) 8 x 11 y 9. (a) 2n1
(b) x 5- (c) x y 1+ -^ h (d) 4x 1+1] g (e) 7a b+
1] g
(f) 2x 1- (g) 21
x 3- (h) 3x4
(i) 7x5 3+9] g (j) 4m
-3
10. (a) 1
a5 (b) n4 (c) 1x + (d)
1x y-
(e) 4 7
1
t 4-] g
(f) a b5 + (g) 1
x3 (h) b34 (i) 2 3x 43 +] g (j)
1
x3
11. | | 2a b+ = | | | | 8a b+ = | | | | | |a b a b` #+ +
12. 1 13. 192
1 14. 689 mL 15. (a) 6 h (b)
127
(c) 81
(d) 33.3% 16. $38 640 17. 70% 18. 6.3 1023#
19. (a) 2x1
(b) y 1- (c) 6x 3+1] g (d) 2 3x 11- -] g (e) 3y
7
20. (a) 1.3 10 5#
- (b) 1.23 1011# 21. (a)
97
(b) 33041
22. (a) 1
x3 (b)
2 51
a + (c) a
b 5c m 23. 14 500
24. | | ,2 5 7LHS = - + - = | | | | .2 5 7RHS = - + - = So | | | | | |a b a b#+ + since .7 7#
Challenge exercise 1
1. 4303278
2. 11811
3. . , %, , .0 502 519951
0 5o
4. 5331
% 5. 161
6. 3.04 1014# 7. 83% 8. 1
99903271
9. 18 h 10. 1.98
11.
2 2 1 22 2 22 2 22 2 1
2 2 1 2 2 2 1
LHS
RHS
k k
k k
k
k
k k k
1
1 1
1
1
1 1
:
`
= - +
= - +
= -
= -
=
- + = -
+
+ +
+
+
+ +
^
^^ ^
h
hh h
12. −2 4 .3 5 13. . , , . , ,0 34 2 1 5 073
- o 14. 632
%
15. ,x
xx
x1
11
11
1when when2 1-
--
- 16. 0.73
17. 0.6% 18 4.54 19. 4.14 10 20#
-
20.
| | | | | | , , ;| | | | | | , , ;a b a b a b a ba b a b b ba
0 0 0 00 0 0 0
when orwhen ora
2 2 1 11 2 1 1 2
+ = +
+ +
| | | |a b a b` #+ + for all a , b
Chapter 2: Algebra and surds
Exercises 2.1
1. 7 x 2. 3 a 3. z 4. 6 a 5. 3 b 6. −3 r
7. y- 8. −5 x 9. 0 10. 3 k 11. 9 t 12. 10 w
13. m- 14. x- 15. 0 16. 5 b 17. 11 b 18. 10x-
19. 6 6x y- 20. 3a b- 21. 4 2xy y+ 22. 6ab2-
23. m m6 122 - + 24. 2 6p p2 - - 25. 8 3x y+
26. 2 10ab b- + 27. 2bc ac- 28. 2 9 1a x5 3- +
29. 2 3 2x xy x y y3 2 2 3- + + 30. 3 7 6x x x3 2+ - -
Exercises 2.2
1. b10 2. xy8 3. p10 2 4. wz6-
5. ab15 6. xyz14 7. abc48 8. d12 2
9. a12 3 10. y27 3- 11. x32 10
12. a b6 2 3 13. a b10 3 2- 14. p q21 3 4
15. a b5 3 3 16. n8 10- 17. k p33 18. t81 12
19. 14m11- 20. x y24 6 3
Exercises 2.3
1. 6 x 2. 2 3. 4a2 4. 8 a 5. 4 a 6. 2
y 7. 3 p
8. 2ab
9. 34y
10. 3x3- 11. 3 a 12. 3
1
ab2 13.
2qs-
14. 3
2
c d2 15.
x
z
2 2
2
16. 6p q4 17. 4c
a b4 7
18. 2ab6
19. 3y
x z3 3
- 20. 2b
a6
13
Exercises 2.4
1. x2 8- 2. h6 9+ 3. a5 10- + 4. xy x2 3+
5. x x22 - 6. a ab6 162 - 7. a b ab2 2 2+ 8. n n5 202 -
9. 3x y x y63 2 2 3+ 10. k4 7+ 11. t2 17-
12. y y4 112 + 13. b5 6- - 14. x8 2-
15. m3 1- + 16. h8 19- 17. d 6- 18. a a2 42 - +
19. x x3 9 52 - - 20. ab a b b2 2 2- + 21. x4 1-
22. y7 4- + 23. b2 24. t5 6- 25. a2 26+
Exercises 2.5
1. 7 10a a2 + + 2. 2 3x x2 + - 3. 2 7 15y y2 + -
4. 6 8m m2 - + 5. 7 12x x2 + + 6. 3 10y y2 - -
7. 2 6x x2 + - 8. 10 21h h2 - + 9. 25x2 -
10. 15 17 4a a2 - + 11. 8 6 9y y2 + - 12. 7 4 28xy x y+ - -
13. 2 3 6x x x3 2- + - 14. 4n2 - 15. 4 9x2 -
16. 16 49y2- 17. 4a b2 2- 18. 9 16x y2 2- 19. 9x2 -
20. 36y2 - 21. 9 1a2 - 22. 4 49z2 -
Answer S1-S5.indd 758 7/11/09 1:26:18 AM
759ANSWERS
23. 2 11 18 18x xy x y2 - + - + 24. 2 2 7 6 3ab b b a2+ - - +
25. x 83 + 26. 27a3 - 27. 18 81a a2 + +
28. 8 16k k2 - + 29. 4 4x x2 + + 30. 14 49y y2 - +
31. 4 12 9x x2 + + 32. 4 4 1t t2 - +
33. 9 24 16a ab b2 2+ + 34. 10 25x xy y2 2- +
35. 4 4a ab b2 2+ + 36. a b2 2- 37. 2a ab b2 2+ +
38. 2a ab b2 2- + 39. a b3 3+ 40. a b3 3-
Exercises 2.6
1. 8 16t t2 + + 2. 12 36z z2 - + 3. 2 1x x2 - +
4. 16 64y y2 + + 5. 6 9q q2 + + 6. 14 49k k2 - +
7. 2 1n n2 + + 8. 4 20 25b b2 + + 9. 9 6x x2- +
10. 9 6 1y y2 - + 11. 2x xy y2 2+ + 12. 9 6a ab b2 2- +
13. 16 40 25d de e2 2+ + 14. 16t2 - 15. x 92 -
16. 1p2 - 17. 36r2 - 18. 100x2 - 19. 4 9a2 -
20. 25x y2 2- 21. 16 1a2 - 22. 49 9x2- 23. 4x4 -
24. 10 25x x4 2+ + 25. 9 16a b c2 2 2- 26. 44
xx
2
2+ +
27. 1
aa
2
2- 28. 2 4 4x y x y y2 2 2 2- - = - + -^ h
29. 2 2 2 2a b a b c c a ab b ac bc c2 2 2 2 2+ + + + = + + + + +] ]g g
30. 1 2 1 2 1 2 2x x y y x x xy y y2 2 2 2+ - + + = + + - - +] ]g g
31. 12a 32. 32 z2- 33. 9 8 3x x2 + -
34. 3 2x xy y x2 2+ + - 35. 14 4n2 -
36. 12 48 64x x x3 2- + - 37. x2 38. 2x x y y4 2 2 4- +
39. 8 60 150 125a a a3 2+ + +
40. 4 16 15 4 4x x x x4 3 2+ + - -
Problem
2,a = 7,b = 9,c = 4,d = 3,e = 8,f = 0,g = 6,h = 1i =
Exercises 2.7
1. y2 3+^ h 2. x5 2-] g 3. m3 3-] g 4. x2 4 1+] g 5. y6 4 3-^ h 6. xx 2+] g 7. m m 3-] g 8. y y2 2+^ h 9. a a3 5 -] g 10. ab b 1+] g 11. xy x2 2 1-] g 12. mn n3 32 +^ h 13. xy x z2 4 -] g 14. a b a6 3 2+ -] g 15. x x y5 2- +^ h 16. q q3 22 3 -_ i 17. b b5 32 +] g 18. a b ab3 22 2 -] g 19. 5)( 7)(m x+ + 20. 1 2y y- -^ ^h h 21. 7 )(4 3 )( y x+ - 22. 2 6 5a x- +] ]g g 23. 2 1t x y+ -] ^g h 24. 3 2 2 3x a b c- + -] ]g g 25. 3 2 3x x2 +] g 26. 3 2q pq3 2 -_ i 27. ab a b3 5 13 2 +^ h 28. 4 6x x2 -] g 29. 5 7 5m n mn2 3 -^ h 30. 4 6 4ab ab2 3 +^ h 31. r r h2r +] g 32. 3 2x x- +] ]g g 33. ( ) ( )x y4 22+ +
34. 1a- +] g 35. ( ) ( )a ab1 4 32 + -
Exercises 2.8
1. 4 2x b+ +] ]g g 2. 3y a b- +^ ]h g 3. 5 2x x+ +] ]g g 4. 2 3m m- +] ]g g 5. d c a b- +] ]g g 6. 1 3x x2+ +] ^g h 7. 5 3 2a b- +] ]g g 8. 2y x x y- +^ ^h h 9. 1 1y a+ +^ ]h g 10. 5 1x x+ -] ]g g 11. 3)(1 )(y a+ + 12. 2)(1 2 )(m y- -
13. 5 2 3x y x y+ -^ ^h h 14. 4a b ab2+ -^ ]h g 15. 5 3x x- +] ]g g 16. 7)( 4)(x x3+ - 17. 3 7x y- -] ^g h 18. 3 4d e+ -] ]g g 19. 4 3x y- +] ^g h 20. 3 2a b+ -] ]g g 21. 3)( 6)(x x2- + 22. 3q p q- +^ ^h h 23. 2 3 5x x2- -] ^g h 24. 3 4a b c- +] ]g g 25. 7 4y x+ -^ ]h g 26. 4)( 5)(x x3- -
27. (2 3)(2 4) (2 3)( )x x x x2 22 2- + = - +
28. ( ) ( )a b a3 2 3+ + 29. 5( 3)(1 2 )y x- +
30. r r2 3r+ -] ]g g
Exercises 2.9
1. 3 1x x+ +] ]g g 2. 4 3y y+ +^ ^h h 3. 1m 2+] g 4. 4t 2+] g 5. 3 2z z+ -] ]g g 6. 1 6x x+ -] ]g g 7. 3 5v v- -] ]g g 8. 3t 2-] g 9. 10 1x x+ -] ]g g 10. 7 3y y- -^ ^h h 11. 6 3m m- -] ]g g 12. 12 3y y+ -^ ^h h 13. 8 3x x- +] ]g g 14. a 2 2-] g 15. 2 16x x- +] ]g g 16. 4 9y y+ -^ ^h h 17. 6 4n n- -] ]g g 18. x 5 2-] g
19. 9 1p p+ -^ ^h h 20. 2 5k k- -] ]g g 21. 4 3x x+ -] ]g g 22. 7 1m m- +] ]g g 23. 10 2q q+ +^ ^h h 24. 5 1d d- +] ]g g 25. 9 2l l- -] ]g g
Exercises 2.10
1. 2 1)( 5)( a a+ + 2. 5 2 1y y+ +^ ^h h 3. 3 7)( 1)( x x+ + 4. 3 2)( 2)( x x+ + 5. 2 3)( 1)( b b- -
6. 7 2)( 1)( x x- - 7. 3 1 2y y- +^ ^h h 8. 2 3 4x x+ +] ]g g 9. 5 2 3p p- +^ ^h h 10. 3 5 2 1x x+ +] ]g g 11. 2 1)( 6)( y y+ - 12. 5 1 2 1x x- +] ]g g 13. 4 1)(2 3)( t t- - 14. 3 4)(2 3)( x x+ -
15. 6 1 8y y- +^ ^h h 16. 4 3 2n n- -] ]g g 17. 4 1 2 5t t- +] ]g g 18. 3 2 4 5q q+ +^ ^h h 19. r r r r4 1 2 6 4 12 3- + - +=] ] ] ]g g g g 20. 2 5 2 3x x- +] ]g g 21. 6 1 2y y- -^ ^h h 22. 2 3 3 2p p- +^ ^h h 23. 8 7)( 3)( x x+ +
24. 3 4 4 9b b- -] ]g g 25. 6 1)( 9)( x x+ -
26. 3 5x 2+] g 27. 4 3y 2+^ h 28. 5 2k 2-] g 29. 6 1a 2-] g 30. 7 6m 2+] g
Answer S1-S5.indd 759 7/25/09 1:31:06 PM
760 Maths In Focus Mathematics Extension 1 Preliminary Course
Exercises 2.11
1. 1y 2-^ h 2. ( 3)x 2+ 3. ( 5)m 2+ 4. ( 2)t 2-
5. ( 6)x 2- 6. 2 3x 2+] g 7. 4 1b 2-] g 8. 3 2a 2+] g 9. 5 4x 2-] g 10. 7 1y 2+^ h
11. 3 5y 2-^ h 12. 4 3k 2-] g 13. 5 1x 2+] g 14. 9 2a 2-] g 15. 7 6m 2+] g 16.
21
t2
+d n 17. 32
x2
-d n 18. 351
y2
+d n
19. 1
x x
2
+c m 20. 52
kk
2
-d n
Exercises 2.12
1. 2)( 2)(a a+ - 2. 3)( 3)(x x+ - 3. 1)( 1)(y y+ -
4. 5 5x x+ -] ]g g 5. 2 7)(2 7)( x x+ - 6. 4 3)(4 3)( y y+ -
7. 1 2 )(1 2 )( z z+ - 8. 5 1 5 1t t+ -] ]g g 9. 3 2 3 2t t+ -] ]g g 10. 3 4 3 4x x+ -] ]g g 11. 2 )( 2 )(x y x y+ -
12. 6 6x y x y+ -^ ^h h 13. 2 3 2 3a b a b+ -] ]g g 14. 10 10x y x y+ -^ ^h h 15. 2 9 2 9a b a b+ -] ]g g 16. 2 2x y x y+ + + -^ ^h h 17. 3)( 1)(a b a b+ - - +
18. 1 1z w z w+ + - -] ]g g 19. 21
21
x x+ -d dn n
20. 3
13
1y y+ -e eo o 21. 2 3 2 1x y x y+ + - +^ ^h h
22. ( )( ) ( )( )( )x x x x x1 1 1 1 12 2 2+ - = + + -
23. 3 2 3 2x y x y3 3+ -_ _i i 24. 4 2 2x y x y x y2 2+ + -_ ^ ^i h h 25. 1)( 1)( 1)( 1)(a a a a4 2+ + + -
Exercises 2.13
1. 2)( 2 4)(b b b2- + + 2. 3 3 9x x x2+ - +] ^g h 3. 1 1t t t2+ - +] ^g h 4. 4)( 4 16)(a a a2- + +
5. 1 )(1 )( x x x2- + + 6. 2 3 4 6 9y y y2+ - +^ _h i 7. ( ) ( )y z y yz z2 2 42 2+ - + 8. 5 )( 5 25 )(x y x xy y2 2- + +
9. 2 3 4 6 9x y x xy y2 2+ - +^ _h i 10. 1 1ab a b ab2 2- + +] ^g h 11. 10 2 )(100 20 4 )( t t t+ - + 2 12.
23
4 23
9x x x2
- + +d en o 13.
10 1 100 10 1a b a ab b2 2
+ - +d en o 14. 1 2 1x y x x xy y y2 2+ - + + + + +^ _h i 15. xy z x y xyz z5 25 306 362 2 2+ - +^ _h i 16. a a 19 2 - +- ^ h 17. 1
31
3 9x x x2
- + +d en o 18. 3 3 9 6x y y y xy x x2 2+ + - - + + +^ _h i 19. 1 4 5 7x y x x xy y y2 2+ - + - + - +^ _h i 20. 2 6 )(4 24 2 6 36)( a b a a ab b b2 2+ - + + + + +
Exercises 2.14
1. x x2 3 3+ -] ]g g 2. p p3 3 4+ -^ ^h h 3. y y y5 1 12- + +^ _h i 4. ) (ab a b a2 2 2 1+ -^ h 5. 5 1a 2-] g 6. x x2 3 4- -- ] ]g g 7. z z z3 5 4+ +] ]g g 8. ab ab ab3 2 3 2+ -] ]g g 9. x xx 1 1+ -] ]g g 10. x x2 3 2 2- +] ]g g 11. 5 3m n- +] ]g g 12. x7 2 1- +] g
13. 5 4 4y y y+ + -^ ^ ^h h h 14. 1 2 2 4x x x x2- + - +] ] ^g g h 15. x x x x x x1 1 1 12 2+ - + - + +] ^ ] ^g h g h 16. x x x2 5+ -] ]g g 17. ( )x x3 3 2+ -] g
18. ( ) ( )xy xyy 2 1 2 1+ - 19. b b b3 2 4 2 2- + +] ^g h 20. x x3 3 2 2 5- +] ]g g 21. x3 1 2-] g 22. 2)( 5)( 5)(x x x+ + - 23. 3z z 2+] g 24. 1 1 2 3 2 3x x x x+ - + -] ] ] ]g g g g 25. x x x y x xy y2 2 2 2 2+ - + - +] ] ^ _g g h i 26. ( ) ( )a a a4 3 3+ - 27. x x xx 2 4 25 2- + +] ^g h 28. 2)( 2)( 3)( 3)(a a a a+ - + - 29. 4 ( 5)k k 2+
30. 3( 1) 1) 3)( (x x x+ - +
Exercises 2.15
1. 4 4 2x x x2 2+ + = +] g 2. 6 9 3b b b2 2- + = -] g 3. 10 25 5x x x2 2- + = -] g 4. 8 16 4y y y2 2+ + = +^ h
5. 14 49 7m m m2 2- + = -] g 6. 18 81 9q x q2 2+ + = +^ h
7. 2 1 1x x x2 2+ + = +] g 8. 16 64 8t t t2 2- + = -] g 9. 20 100 10x x x2 2- + = -] g 10. 44 484 22w w w2 2+ + = +] g 11. 32 256 16x x x2 2- + = -] g 12. 3
49
23
y y y22
+ + = +d n
13. 74
4927
x x x22
- + = -d n 14. 41
21
a a a22
+ + = +d n
15. 94
8129
x x x22
+ + = +d n 16. 5
yy
y1625
45
22
2
- + = -d n
17. 11
kk
k16
1214
112
22
- + = -d n
18. 6 9 3x xy y x y2 2 2+ + = +^ h 19. 4 4 2a ab b a b2 2 2- + = -] g 20. 8 16 4p pq q p q2 2 2- + = -^ h Exercises 2.16
1. 2a + 2. 2 1t - 3. 3
4 1y + 4.
2 14
d - 5.
5 2xx-
6. 4
1y -
7. ab a
322
-
-] g 8.
31
ss+
- 9.
11
bb b2
+
+ +
10. 3
5p + 11.
31
aa+
+ 12.
2 4
3
x x
y2 + +
+ 13. 3x -
14. 4 2 1
2
p p
p2 - +
- 15.
2a ba b
-
+
Answer S1-S5.indd 760 7/11/09 1:26:21 AM
761ANSWERS
Exercises 2.17
1. (a) 45x
(b) 15
13 3y + (c)
128a +
(d) 6
4 3p + (e)
613x -
2. (a) 2 1a
b-
(b) 1
2 1
q
p q q2
+
- - +^ _h i (c)
b
x yb
2 1
2
10
2
-
+
]^
gh
(d) ab
x xy y2 2- + (e)
5 2
3 1
x x
x x
- -
- -
] ]] ]
g gg g
3. (a) 5x (b)
xx
x 12
-
- +
] g (c) 3
a ba b
+
+ + (d)
22
xx+
(e) p q
p q p q
p q
p q 11 2 2
+
+ -=
+
- ++^ ^h h (f)
x x
x
1 3
12
+ -
-
] ]]g gg
(g) 2 23 8
x xx
+ -
- +
] ]g g (h) 1
2
a
a2+
+
] g
(i) y y y
y y
2 3 1
3 14 132 2
+ + -
+ +
^ ^ ^_h h h
i (j)
x x x
x
4 4 3
5 22
+ - +
+-
] ] ]]g g g
g
4. (a) y y
xx
3 9
2
8
2
2 - +
+
_]
ig
(b) 15
2 1
y
y y+ +^ ^h h
(c) x x
x x2 3 4
10 242
- -
+ -
] ]g g (d) b
b bb 1
3 5 102
2
+
- -
] g (e) x
5. (a) 5 2 3
3 13x x x
x- - +
-
] ] ]g g g (b) 2 2
3 5x x
x+ -
-
] ]g g
(c) p q p q
p pq q
pq
3 5 22 2
+ -
+ -
^ ^h h (d) 2 1
a b a ba ab b2 2
+ -
- - +
] ]g g
(e) x y x y
x yy 1
+ -
+ +
^ ^^h h
h
Exercises 2.18
1. (a) 7.1- (b) 6.9- (c) 48.1 (d) 37.7- (e) 0.6
(f) 2.3 (g) 5.3- 2. 47 3. 7- 4. 375 5. 196-
6. 5.5 7. 377 8. 284 9. 40- 10. 51.935 11. 143
-
12. 22.4 13. 1838.8 14. 43
15. 15 16. 10
17. 2 3 18. 23.987 19. 352.47 20. 93 21. 4
Exercises 2.19
1. (a) 2 3 (b) 3 7 (c) 2 6 (d) 5 2 (e) 6 2
(f) 10 2 (g) 4 3 (h) 5 3 (i) 4 2 (j) 3 6
(k) 4 7 (l) 10 3 (m) 8 2 (n) 9 3 (o) 7 5
(p) 6 3 (q) 3 11 (r) 5 5
2. (a) 6 3 (b) 20 5 (c) 28 2 (d) 4 7 (e) 16 5
(f) 8 14 (g) 72 5 (h) 30 2 (i) 14 10 (j) 24 5
3. (a) 18 (b) 20 (c) 176 (d) 128 (e) 75
(f) 160 (g) 117 (h) 98 (i) 363 (j) 1008
4. (a) 45x = (b) 12x = (c) 63x = (d) 50x =
(e) 44x = (f) 147x = (g) 304x = (h) 828x =
(i) 775x = (j) 960x =
Exercises 2.20
1. 3 5 2. 2 3. 6 3 4. 3 3 5. 3 5- 6. 3 6
7. 7 2- 8. 8 5 9. 4 2- 10. 4 5 11. 2 12. 5 3
13. 3- 14. 2 15. 5 7 16. 2 17. 13 6
18. 9 10- 19. 47 3 20. 2 2 35 - 21. 7 5 2-
22. 2 3 4 5- - 23. 7 6 3 5+ 24. 2 2 3- -
25. 17 5 10 2- +
Exercise 2.21
1. 21 2. 15 3. 3 6 4. 10 14 5. 6 6- 6. 30
7. 12 55- 8. 14 9. 60 10. 12 2 3=
11. 2 48 8 3= 12. 15 28 30 7=
13. 2 20 4 5= 14. 84- 15. 2
16. 28 17. 30 18. 2 105- 19. 18
20 . 30 50 150 2= 21. 2 6 22. 4 3 23. 1 24. 6
8
25. 2 3 26. 3 10
1 27.
2 5
1 28.
3 5
1 29.
21
30. 2 2
3 31.
2
3 32.
2 5
9 33.
2 2
5 34.
32
35. 75
Exercises 2.22
1. (a) 10 6+ (b) 2 6 15- (c) 12 8 15+
(d) 5 14 2 21- (e) 6 4 18 6 12 2- + = - +
(f) 5 33 3 21+ (g) 6 12 6- - (h) 5 5 15-
(i) 6 30+ (j) 2 54 6 6 6 6+ = +
(k) 8 12 12 8 24 3- + = - + (l) 210 14 15-
(m) 10 6 120- (n) 10 2 2- - (o) 4 3 12-
2. (a) 10 3 6 3 5 9 3+ + +
(b) 10 35 2 14- - +
(c) 2 10 6 10 15 15 6- + -
(d) 12 18 8 1224 36 8 12
20 60 10 305 15 10 30
+ - - =
+ - -
(e) 52 13 10- (f) 15 15 18 10 6 6- + -
(g) 4 (h) 1- (i) 12- (j) 43 (k) 3 (l) 241-
(m) 6- (n) 7 2 10+ (o) 11 4 6- (p) 25 6 14+
(q) 57 12 15+ (r) 27 4 35-
(s) 77 12 40 77 24 10- = - (t) 53 12 10+
3. (a) 18 (b) 108 2 (c) 432 2 (d) 19 6 2+ (e) 9
4. (a) 21, 80a b= = (b) 19, 7a b= = -
5. (a) 1a - (b) p pp2 1 2 1- - -^ h 6. 25k = 7. 2 3 5x y xy- - 8. 17, 240a b= =
9. 107, 42a b= = - 10. 9 5 units2+
Answer S1-S5.indd 761 8/2/09 2:47:53 AM
762 Maths In Focus Mathematics Extension 1 Preliminary Course
Exercises 2.23
1. (a) 77
(b) 46
(c) 5
2 15 (d)
106 14
53 14
=
(e) 3
3 6+ (f)
212 5 2-
(g) 5
5 2 10+
(h) 14
3 14 4 7- (i)
208 5 3 10+
(j) 35
4 15 2 10-
2. (a) 4 4 3 243 2- -= ^ h (b) 47
6 7 3+- ^ h
(c) 19
2 15 4 1819
15 6 22-=
-- -^ ^h h
(d) 13
19 8 313
8 3 19-=
-- ^ h (e) 6 2 5 3 5 2+ + +
(f) 2
6 15 9 6 2 10 6- + -
3. (a) 2 2
(b) 2 3 32 6 3 2 3 3 6 2 3- + - + = - - + -^ h
(c) 39
22 5 14 2+
(d)
106 6 16 3 84 8 14
6 21 145
3 8 3 4
- - - +
=- + + -
^ h
(e) 4- (f) 4 2
(g) 15
20 12 19 6 25 3 615
19 6 65 3 6+ + -=
+ -
(h) 6
6 9 2 2 3+ + (i)
214 6 9 3+
(j) 415
30330 30 5- -
(k) 13
28 2 6 7 3- -
(l) 2
2 15 2 10 2 6 3 5+ - - -
4. (a) 45, 10a b= = (b) 1, 8a b= = (c) 21
,21
a b= - =
(d) 195
,98
a b= - = - (e) 5, 32a b= =
5.
2
2
3 2 23
2 1
2 1
2
4
2 1
2 1
2 1
2 1
2
4
2
2
2 1
2 1 2 12
4 2
2 12 2 2 1
2
13 2 2
2
2 2
2 2
# #
+
-+
=+
-
-
-+
=-
- -+
=-
- - ++
=-
+
= - +
=
^^ ^
hh h
So rational
6. (a) 4 (b) 14 (c) 16
7. 3
3 5 2 15 3- - -
8. 3 2 2
2
2
8
3 2 2
2
3 2 2
3 2 2
2
8
2
2
3 2 2
2 3 2 22
8 2
9 4 26 4 2
4 2
16 4 2
4 2
6 4 2 4 26
2 2
# #
#
++
=+ -
-+
=-
-+
=-
-+
=-
+
= - +
=
^^
hh
So rational
9. x 3 2= - +^ h 10. 4
4 4b
b b-
+ +
Test yourself 2
1. (a) 2y- (b) 4a + (c) 6k5- (d) 15
5 3x y+ (e) 3 8a b-
(f) 6 2 (g) 4 5
2. (a) 6 6x x+ -] ]g g (b) 3 1a a+ -] ]g g (c) ab b4 2-] g (d) 3)(5 )(y x- + (e) n p2 32 - +^ h (f) 2 )(4 2 )( x x x2- + +
3. (a) 4 6b - (b) 2 5 3x x2 + - (c) 4 17m +
(d) 16 24 9x x2 - + (e) 25p2 - (f) 1 7a- -
(g) 2 6 5 3- (h) 3 3 6 21 2 7- + -
4. (a) a ab 3 9
822 + +^ h (b)
2
15
m 2-] g
5. 157.464V = 6. (a) 17 (b) 17
6 15 9-
7. 3 2
4 5x x
x+ -
+
] ]g g 8. (a) 36 (b) 2- (c) 2 (d) 216 (e) 2
9. (a) 5
1 (b) 8 10. 11.25d =
11. (a) 15
2 3 (b)
22 6+
12. (a) 3 6 6 4 3 4 2- - + (b) 11 4 7+
13. (a) 3( 3)( 3)x x- + (b) x x6 3 1- +] ]g g (c) y y y5 2 2 42+ - +^ _h i
14. (a) 3y
x4
3
(b) 3 1
1x -
15. (a) 99 (b) 24 3
16. (a) a b2 2- (b) 2a ab b2 2+ + (c) 2a ab b2 2- +
17. (a) a b 2-] g (b) a b a ab b2 2- + +] ^g h 18.
23 3 1+
19. (a) 4 3
abb a+
(b) 10
3 11x -
20. 7
21 5 46 2- -
Answer S1-S5.indd 762 7/12/09 1:31:58 AM
763ANSWERS
21. (a) 6 2 (b) 8 6- (c) 2 3 (d) 3
4 (e) 30a b2
(f) 3n
m4 (g) 2 3x y-
22. (a) 2 6 4+ (b) 10 14 5 21 6 10 3 15- - +
(c) 7 (d) 43 (e) 65 6 14-
23. (a) 7
3 7 (b)
156
(c) 5 1
2+
(d) 15
12 2 6- (e)
5320 3 15 4 10 3 6+ + +
24. (a) 10
10x + (b)
2117 15a -
(c) ( 1)( 1)x x
x3 2+
-
-
(d) 1
1k -
(e) 3
15 6 15 3 15 2- - -
25. (a) 48n = (b) 175n = (c) 392n =
(d) n 5547= (e) 1445n =
26. 312171
27. (b), (c) 28. (d) 29. (a), (d) 30. (c)
31. (c) 32. (b) 33. (a) 34. (d) 35. (b)
Challenge exercise 2
1. (a) 2 8 6a b ab a2 2 3- + (b) 4y4 -
(c) 8 60 150 125x x x3 2- + -
2. 17
17 3 2 5 20+ + 3.
2 2
142
or
4. ab
xa
bx
ab
x4 2
2
2
2 2
+ + += d n
5. (a) x x4 9+ +] ]g g (b) ( ) ( )x y x y x y x y x y3 2 3 3 22 2 2- + = + - +_ _ _i i i (c) 5 7 25 35 49x x x2+ - +] ^g h (d) 2 2 2b a a- + -] ] ]g g g
6. 4 12 9 2 3x x x2 2+ + = +] g 7. x
y
1
1
2 -
+
] g 8. 2 5
9. 1
1
a a
a2
2
- +
+] g 10.
2 2x b
ax b
a+ -d dn n
11. x x x
x x x xy y
3 3 2
3 6 3 643 2
- + -
- + + -
] ] ]g g g
12. (a) 8 12 6 1x x x3 2- + - (b) 2 1
3 4
x
x2-
+
] g
13. x x x 97 153 2 + --
14. 13
66 6 4 2 15 4 5 65 3- + - + -
15. xx
x32
91
312
2
+ + = +d n 16. 2x =
17. 10
400 59 5- 18. (a) 3
12171
(b) ,a b2317
2314
= = -
19. 121
i = 20. 4
r4
3 3
r r
r= =
21. 2 6 3s = +
Chapter 3: Equations
Exercises 3.1
1. 5t = - 2. 5.6z = - 3. 1y = 4. 6.7w = 5. 12x =
6. 4x = 7. 151
y = 8. 35b = 9. 16n = - 10. 4r =
11. 9y = 12. 6k = 13. 2d = 14. 5x = 15. 15y =
16. 20x = 17. 20m = 18. 4x = 19. 7a = - 20. 3y =
21. 4b = - 22. 3x = 23. 132
a = - 24. 4t = -
25. 1.2x = 26. 1.6a = 27. 81
b = 28. 39t =
29. 5p = 30. 4.41x Z
Exercises 3.2
1. 331
b = 2. 35x = 3. 494
y = 4. 1359
x = 5. 585
k =
6. 36x = 7. 0.6t = 8. 3x = - 9. 1.2y = - 10. 69x =
11. 13w = 12. 30t = 13. 14x = 14. 1x = -
15. 0.4x = - 16. 3p = 17. 8.2t = 18. 9.5x = -
19. 22q = 20. 3x = - 21. 0.8b = 22. 0.375a = -
23. 3x = 24. 1y = 25. 132
t = -
Exercises 3.3
1. 8.5t = 2. 122l = 3. 8b = 4. 41a = 5. 4y =
6. 6.68r = 7. 6.44x = 8. 15n = 9. 332
y1 =
10. 3.7h = 11. (a) 25.39BMI = (b) 69.66w =
(c) 1.94h = 12. 0.072r = 13. 9x1 = - 14. 2.14t =
15. x 2!= 16. 2.12r = 17. 10.46r = 18. 1.19x =
19. 5.5x = 20. 3.3r =
Exercises 3.4
1. (a) x 32
-4 -3 -2 -1 0 1 2 3 4
(b) y 4#
-4 -3 -2 -1 0 1 2 3 4
2. (a) 7t 2 (b) x 3$ (c) 1p 2 - (d) x 2$ - (e) 9y 2 -
(f) a 1$ - (g) y 221
$ - (h) x 21 - (i) a 6# -
(j) y 121 (k) b 181 - (l) 30x 2 (m) x 343
#
(n) m 1432
2 (o) b 1641
$ (p) r 9# - (q) 8z 2
Answer S1-S5.indd 763 8/2/09 2:47:54 AM
764 Maths In Focus Mathematics Extension 1 Preliminary Course
(r) w 254
1 (s) x 35$ (t) t 9$ - (u) 6q52
2 -
(v) 1x32
2 - (w) b 1141
# -
3. (a) x1 71 1
0 1 2 3 4 5 6 7 8
(b) p2 51#-
-3 -2 -1 0 1 2 3 4 5
(c) x1 41 1
-3 -2 -1 0 1 2 3 4 5
(d) y3 5# #-
-3 -2 -1 0 1 2 3 4 5
(e) y61
132
1 1
-3 -2 -1 0 1 2 3 4 5
Exercises 3.5
1. (a) x 5!= (b) y 8!= (c) 4 4a1 1-
(d) ,k k1 1$ # - (e) 6, 6x x 12 -
(f) p10 10# #- (g) 0x = (h) ,a a14 142 1 -
(i) 12 12y1 1- (j) ,b b20 20$ # -
2. (a) ,x 5 9= - (b) ,n 4 2= - (c) ,a a2 212 -
(d) x4 6# # (e) ,x 3 6= - (f) ,x 5 475
= -
(g) 3 2y211 1- (h) ,x x9 6$ # - (i) x 12!=
(j) a2 10# #
3. (a) 141
x = (b) ,a 331
= - (c) 231
b =
(d) No solutions (e) 272
y = - (f) 7x = (g) ,m 5 132
=
(h) ,d 221
143
= - (i) ,y54
2= - (j) No solutions
4. (a) ,x 221
= - (b) 3, 231
y = (c) 10, 153
a = -
(d) ,x 4 731
= - (e) ,d 4 5= -
5. (a) ,t 3 152
= - (b) 1 3t521 1-
-3 -2 -1 0 1 2 3 4 5
Exercises 3.6
1. (a) 3x = (b) y 8!= (c) 2n != (d) 2x 5!=
(e) 10p = (f) x 5!= (g) y 3!= (h) 2w =
(i) n 4!= (j) 2q = -
2. (a) 6.71p != (b) 4.64x = (c) 2.99n = (d) 5.92x !=
(e) 1.89y = (f) .d 2 55!= (g) 4.47k != (h) 2.22x =
(i) .y 3 81!= (j) 3.01y =
3. (a) 27n = (b) 16t = (c) 32x = (d) 8t =
(e) 243p = (f) 625m = (g) 216b = (h) 27y =
(i) 128a = (j) 81t =
4. (a) 51
x = (b) 21
a = (c) 21
y = (d) x71
!=
(e) 32
n = (f) 2a = (g) 2x != (h) 9b =
(i) x32
!= (j) b 121
!=
5. (a) x512
1= (b) 6
41
x = (c) 811
a = (d) 625
1k =
(e) x81
= (f) 4x = (g) 8y = (h) n 73219
=
(i) 8b = (j) 1216127
m =
6. (a) 4n = (b) 5y = (c) 9m = (d) 5x = (e) 0m =
(f) 3x = (g) 2x = (h) 2x = (i) 1x = (j) k 2=
7. (a) 2x = (b) 1x = (c) 2x = - (d) 2n = (e) 0x =
(f) 6x = (g) y31
= (h) 2x = (i) 2x = (j) a 0=
8. (a) 21
m = (b) 31
x = (c) 31
x = (d) 21
k = -
(e) 32
k = - (f) 43
n = (g) 121
x = (h) 32
n =
(i) 61
k = - (j) 132
x =
9. (a) x 1= - (b) x 131
= - (c) k 4= - (d) n 3=
(e) x 212
= - (f) x32
= - (g) x 421
= - (h) x 1117
= -
(i) x 154
= (j) x 18=
10. (a) 41
m = (b) 243
k = - (c) 283
x = (d) 121
k =
(e) 181
n = (f) 21
n = - (g) 54
x = (h) 361
b = -
(i) 171
x = - (j) 5m =
Puzzle
1. All months have 28 days. Some months have more days as well. 2. 10 3. Bottle $1.05; cork 5 cents
4. 16 each time 5. Friday
Exercises 3.7
1. ,y 0 1= - 2. ,b 2 1= - 3. ,p 3 5= - 4. ,t 0 5=
5. ,x 2 7= - - 6. q 3!= 7. x 1!= 8. ,a 0 3= -
Answer S1-S5.indd 764 8/2/09 2:47:55 AM
765ANSWERS
9. ,x 0 4= - 10. x21
!= 11. ,x 1 131
= - -
12. ,y 1 121
= - 13. ,b43
21
= 14. ,x 5 2= - 15. ,x 032
=
16. ,x 1 221
= 17. 0, 5x = 18. 1, 2y = - 19. ,n 53=
20. 3, 4x = 21. 6, 1m = - 22. , ,x 0 1 2= - -
23. , ,y 1 5 2= - - 24. ,x 5 7= - 25. ,m 8 1= -
Exercises 3.8
1. (a) x 5 2!= - (b) 3a 7!= + (c) 4y 23!= +
(d) 1x 13!= - (e) p 44 7 2 11 7! != - = -
(f) x 28 5 2 7 5! != + = +
(g) 510y 88 2 22 2210 2! ! ! -= - = - = ^ h (h) 1x 2!= + (i) 12n 137!= -
(j) 3
y25!
=+
2. (a) . , .x 3 45 1 45= - (b) . , .x 4 59 7 41= - -
(c) . , .q 0 0554 18 1= - (d) . , .x 4 45 0 449= -
(e) . , .b 4 26 11 7= - - (f) . , .x 17 7 6 34=
(g) . , .r 22 3 0 314= - (h) . , .x 0 683 7 32= - -
(i) . , .a 0 162 6 16= - (j) . , .y 40 1 0 0749= -
Exercises 3.9
1. (a) . , .y 0 354 5 65= - - (b) , .x 1 1 5=
(c) . , .b 3 54 2 54= - (d) , .x 1 0 5= -
(e) . , .x 0 553 0 678= - (f) . , .n 0 243 8 24= -
(g) ,m 2 5= - - (h) ,x 0 7= (i) ,x 1 6= -
(j) . , .y 2 62 0 382=
2. (a) x2
1 17!=
- (b) x
65 13!
=
(c) q2
4 282 7
!!= =
(d) h8
12 1282
3 2 2! !=
-=
-
(e) s6
8 403
4 10! != =
(f) x2
11 133!=
- (g) d
125 73!
=-
(h) x2
2 321 2 2
!!= = (i) t
21 5!
=
(j) x4
7 41!=
Exercises 3.10
1. ,y y1 02 1 2. x021
1 1 3. 0, 1x x21
21
4. m072
1 # 5. ,x x53
0>1 - 6. b2 01#-
7. x1 141
1 1 8. z351
31 1- - 9. x2 243
1 #
10. ,x x2 261
1 2 11. x495
41#- -
12. x131
1157
1 1 13. ,a a341
221
1 2- -
14. x21
95
1 1 15. ,y y2 11 2- -
16. ,x x87
42# - 17. 4 26p21
11
18. ,x x151
2# - - 19. ,t t52
232
2#
20. 0m981 1- 21. 5, 0 1x x1 1 1-
22. ,n n0 2 41 # $ 23. ,x x5 3 01 12 -
24. 2, 1 6m m1# #- - 25. ,x x1 3 41# #-
26. ,x x221
32
1# #- 27. ,x x3 1 21$ #-
28. ,n n1 3 51 1 1- 29. ,x x432
74
1 1 1- - -
30. ,x x21
1 71# #
Exercises 3.11
1. 3 0x 11- 2. 0 4y1 1 3. ,n n0 1# $
4. ,x x2 2# $- 5. ,n n1 11 2- 6. n5 3# #-
7. ,c c1 21 2- 8. x4 2# #- - 9. 4 5x1 1
10. ,b b221
# $- - 11. ,a a131
1 2-
12. ,y y121
21 2- 13. ,x x32
1# $
14. ,b b352
1 2- 15. x121
31
# #- -
16. y4 3# #- 17. ,x x4 41 2- 18. a1 1# #-
19. 2 3x 11- 20. ,x x1 3# $- 21. 0 2x1 1
22. a1 121
# # 23. ,y y254
# $-
24. ,m m132
121
1 2- 25. x1 131
# #
26. 0 x21
11 27. ,x x021
1 $
28. ,y y154
1 2- - 29. 3 3n21
1 #
30. ,x x8 52# - - 31. ,x x52
73
1 2
32. ,x x451
52# 33. ,x x141
12# - -
34. ,x x3 21 2- 35. x43
53
1#- -
Answer S1-S5.indd 765 7/11/09 1:26:27 AM
766 Maths In Focus Mathematics Extension 1 Preliminary Course
Exercises 3.12
1. ,a b1 3= = 2. ,x y2 1= = 3. ,p q2 1= = -
4. ,x y6 17= = 5. ,x y10 2= - = 6. ,t v3 1= =
7. ,x y3 2= - = 8. ,x y64 39= - = - 9. ,x y3 4= = -
10. ,m n2 3= = 11. ,w w1 51 2= - = 12. ,a b0 4= =
13. ,p q4 1= - = 14. ,x x1 11 2= = -
15. ,x y1 4= - = - 16. ,s t2 1= = -
17. ,a b2 0= - = 18. ,k h4 1= - =
19. ,v v2 41 2= - = 20. , .x y2 1 41Z=
Problem
23 adults and 16 children.
Exercises 3.13
1. ,x y0 0= = and ,x y1 1= =
2. ,x y0 0= = and ,x y2 4= - =
3. ,x y0 3= = and ,x y3 0= =
4. ,x y4 3= = - and ,x y3 4= = - 5. ,x y1 3= - = -
6. ,x y3 9= = 7. ,t x2 4= - = and ,t x1 1= =
8. ,m n4 0= - = and ,m n0 4= = -
9. ,x y1 2= = and ,x y1 2= - = -
10. ,x y0 0= = and ,x y1 1= =
11. ,x y2 1= = and ,x y1 2= - = - 12. ,x y0 1= =
13. ,x y1 5= = and ,x y4 11= =
14. ,x y41
4= = and ,x y1 1= - = - 15. ,t h21
41
= - =
16. ,x y2 0= =
17. ,x y0 0= = and ,x y2 8= - = - and ,x y3 27= =
18. ,x y0 0= = and ,x y1 1= = and ,x y1 1= - =
19. ,x y21
243
= = 20. 135
,1312
x y= - = -
Exercises 3.14
1. , ,x y z2 8 1= - = - = - 2. , ,a b c2 1 2= - = - =
3. , ,a b c4 2 7= - = = 4. , ,a b c1 2 3= = = -
5. , ,x y z5 0 2= = = - 6. , ,x y z0 5 4= = - =
7. , ,p q r3 7 4= - = = 8. , ,x y z1 1 2= = - =
9. , ,h j k3 2 4= - = = - 10. , ,a b c3 1 2= = - = -
Test yourself 3
1. (a) 10b = (b) 116a = - (c) 7x = -
(d) ,x x431
32# - - (e) p 4#
2. (a) 1262.48A = (b) 8558.59P =
3. (a) x x x8 16 42 2- + = -] g (b) k k k4 4 22 2+ + = +] g 4. (a) ,x y2 5= - = (b) ,x y4 1= = and ,x y
21
8= - = -
5. (a) 2x = (b) 41
y =
6. (a) ,b 2 131
= - (b) ,g 241
= (c) ,x x4 3$ #
7. (a) 36A = (b) 12b = 8. ,x21
1=
9. 1 3y1 #-
10. (a) . , .x 0 298 6 70= - - (b) . , .y 4 16 2 16= -
(c) . , .n 0 869 1 54= -
11. (a) 764.5V = (b) 2.9r = 12. x 7141
2
13. ,x x2 91 2 14. . , .x y2 4 3 2= = 15. (a) 2100V =
(b) 3.9r = 16. (a) ii (b) i (c) ii (d) iii (e) iii
17. , ,a b c3 2 4= = = -
18. ,n n0 331
2 1 -
19. 4x = - 20. 2x = - 21. (a) 3y 2 (b) n3 0# #-
(c) 2x = (d) 2x = (e) ,x 3 152
= - (f) 1, 2t t$ # -
(g) 4 2x# #- (h) 3x = - (i) ,y y2 22 1 -
(j) 1, 1x x# $- (k) 65
x = (l) 21
2b# #-
(m) No solutions (n) 231
,53
t = (o) 1 3x1 1-
(p) ,m m3 2# $- (q) ,t t1 01 2- (r) 1 3y1 1
(s) 2 252
n1 # (t) x21
51
1 #-
Challenge exercise 3
1. 1y = 2. ,x a x a1 2- 3. ,a b3 2!= =
4. . , .x 2 56 1 56= - 5. ,y y2 0 31# #-
6. ; ,x x x x x x3 3 2 2 4 3 22!+ - - + + =] ] ] ^g g g h
7. ,x y1 2= = and ,x y1 0= - =
8. ; . , .b x4 17 4 8 12 0 123! Z= = + - 9. x 1!=
10. 1 1t1 1- 11. x3 8# #- 12. 41
x =
13. 2.31r = 14. No solutions 15. x b a a2!= + +
16. ,y y221
32
1# #- 17. 2247.36P =
18. x3
4 102 !=^ h
19. , . .x x4 2 2 0 71 1 1- -
20. ,y y153
1 2-
Answer S1-S5.indd 766 7/25/09 1:31:09 PM
767ANSWERS
Chapter 4 : Geometry 1
Exercises 4.1
1. (a) 47y c= (b) 39x c= (c) 145m c= (d) 60y c= (e) 101b c= (f) 36x c= (g) 60a c= (h) 45x c= (i) 40y c= (j) 80x c= 2. (a) 121c (b) 72 29c l (c) 134 48c l 3. (a) 42c (b) 55 37c l (c) 73 3c l
4. (a) (i) 47c (ii) 137c (b) (i) 9c (ii) 99c (c) (i) 63c (ii) 153c (d) (i) 35c (ii) 125c (e) (i) 52c (ii) 142c (f) (i) 15c7l (ii) 105c7l (g) (i) 47c36l (ii) 137c36l (h) (i) 72c21l (ii) 162c21l (i) (i) 26c 11 l (ii) 116c 11 l (j) (i) 38c 15 l (ii) 128c 15 l 5. (a) 49x c= (b) 41c (c) 131c 6. (a) ,y x z15 165c c= = =
(b) , ,x y z142 48 28c c c= = =
(c) , ,a b c43 137 101c c c= = =
(d) ,,a b d c97 41 42c c c= = = =
(e) , ,a b c68 152 28c c c= = = (f) ,a b10 150c c= =
7. 0x x x x
xx
8 10 2 10 10 7 10 36
18 36020
- + - + + + + =
=
=
(angleof revolution)
( )
( )
ABE x
EBC x
ABE EBC
8 108 20 101502 102 20 1030150 30180
c
cc cc
+
+
+ +
= -= -
== -= -
=+ = +
=
ABC`+ is a straight angle
( )
DBC x
DBC EBC
7 107 20 10150150 30180
cc cc
+
+ +
= +
= +
=
+ = +
=
DBE`+ is a straight angle AC and DE are straight lines
8.
AFC x
CD bisects
`
`
+ =
AFE+
( )
( )
( )
( )
DFB x
x
CFE x x
xAFC CFE
AFB
AFB
180 180
180 180 2
is a straight angle
(vertically opposite angles)
is a straight angle
`
c c
c c
+
+
+ +
+
+
= - -
=
= - + -
=
=
9. ABD DBC+ ++
110 3 3 70180
x xc
= - + +
=
So ABC+ is a straight angle. AC is a straight line.
10. AEB BEC CED+ + ++ +
y y y50 8 5 20 3 60
90c= - + - + +
=
So AED+ is a right angle.
Exercises 4.2
1. (a) ,a b e f c d g148 32c c= = = = = = =
(b) ,x z y70 110c c= = =
(c) , ,x y z55 36 89c c c= = = (d) ,y x z125 55c c= = =
(e) ,n e g a c z x 98c= = = = = = = 82o m h f b d y w c= = = = = = = =
(f) , ,a b c95 85 32c c c= = =
(g) , ,a b c27 72 81c c c= = =
(h) , , ,x y z a b56 124 116 64c c c c= = = = =
(i) 61x c= (j) 37y c=
2. (a) CGF
BFG CGF
180 121
5959
( is a straight angle)FGH
`
c c
cc
+
+ +
= -
=
= =
These are equal alternate angles. AB CD` < (b) BAC 360 292 68
(angle of revolution)c c c+ = - =
BAC DCA 68 112180
` c cc
+ ++ = +
=
These are supplementary cointerior angles.
AB CD` <
(c) 180 76104
104
BCD
ABC BCDc
c
+
+ +
= -
=
= =
( BCE+ is a straight angle)
These are equal alternate angles.
AB CD` ;
(d) 180 12852
52
CEF
CEF ABEc
c
+
+ +
= -
=
= =
( CED+ is a straight angle)
These are equal corresponding angles.
AB CD` ;
(e) 180 23 115CFH+ = - +] g ( EFG+ is a straight angle)
42c=
42BFD` c+ = (vertically opposite angles)
ABF BFD 138 42
180c cc
+ ++ = +
=
These are supplementary cointerior angles. AB CD` ;
Answer S1-S5.indd 767 7/12/09 1:32:20 AM
768 Maths In Focus Mathematics Extension 1 Preliminary Course
Exercises 4.3
1. (a) 60x c= (b) 36y c= (c) 71m c= (d) 37x c=
(e) 30x c= (f) 20x c= (g) 67x c= (h) 73a c=
(i) , ,a b c75 27 46c c c= = =
(j) , ,a b c36 126 23c c c= = =
(k) , ,x y z w67 59 121c c c= = = =
2. All angles are equal. Let them be x . x x x 180Then (angle sum of )D+ + =
xx
3 18060
=
=
So all angles in an equilateral triangle are 60 .c
3. x90 c-] g
4. 50
180 (50 45 )ACBABC
DEC ABC85
85
(vertically opposite angles)(angle sum of )
`
cc c cc
c
++
+ +
D
=
= - +
=
= =
These are equal alternate angles.
AB DE` <
5.
124 68
ACB
CBACBA
CBA ACBABC
180 12456
68 124
5656
is isosceles
( is a straight angle)
(exterior angle of )
DCB
`
`
c cc
c cc cc
c
+
++
+ +D
D
= -
=
+ =
= -
=
= =
6. 38y c=
7. (a) x 64c= (b) ,x y64 57c c= = (c) 63x c=
(d) ,a b29 70c c= =
8. 180 (35 25 )120180 12060180 (90 30 )60180 (60 60 )60
HJI
IJL
JIL
ILJ
(angle sum of )
( is a straight angle)
(angle sum of )
(angle sum of )
HJI
HJL
IKL
JIL
c c ccc ccc c cc
c cc
+
+
+
+
D
D
D
= - +
=
= -
=
= - +
=
= - +
=
Since 60 ,IJL JIL ILJ c+ + += = = IJLD is equilateral
( )
( )
( )
KJL
JLK
KJI
JKL
180 60120180 30 12030
is a straight angle
angle sum of
c cc
c c cc
+
+ D
= -
=
= - +
=
°JLK JKL 30`+ += =
JKL` D is isosceles
9. BC BD=
BDC 46` c+ = (base angles of isosceles triangle)
CBD 180 2 4688
#c
+ = -=
CBD BDE 88` c+ += = These are equal alternate angles.
AB ED` ;
10. 18032
OQP 75 73c
+ = - +
=
] g (angle sum of triangle)
MNO OQP 32` c+ += =
These are equal alternate angles.
MN QP` ;
Exercises 4.4
1. (a) Yes
5AB EF cm= = (given)
6BC DF cm= = (given)
8AC DE cm= = (given)
ABC DEF` /D D ( SSS )
(b)Yes
4.7XY BC m= = (given)
XYZ BCA 110c+ += = (given)
2.3YZ AC m= = (given)
XYZ ABC` /D D ( SAS )
(c) No
(d) Yes
PQR SUT 49c+ += = (given)
PRQ STU 52c+ += = (given)
8QR TU cm= = (given)
PQR STU` /D D ( AAS )
(e) No
2. (a)
,
AB KLB L
BC JLABC JKL
438
5by SAS
(given)(given)(given)
`
c+ +
/D D
= =
= =
= =
(b)
,
Z BXY ACYZ BC
RHS XYZ ABC
9072
by
(given)(given)(given)
`
c+ +
/D D
= =
= =
= =
(c)
,
MN QRNO PRMO PQ
MNO PQR
885
by SSS
(given)(given)(given)
` /D D
= =
= =
= =
(d)
.
Y TZ S
XY TRXYZ STR
90351 3
by AAS,
(given)(given)(given)
`
cc
+ ++ +
/D D
= =
= =
= =
(e)
,
BC DEC E
AC EFABC DEF
490
7by SAS
(given)(given)(given)
`
c+ +
/D D
= =
= =
= =
3. (a) B CBDA CDA
ADABD ACD
90is common
by AAS,
(base angles of isosceles )(given)
`
c+ +
+ +
/D D
D=
= =
Answer S1-S5.indd 768 8/2/09 2:47:56 AM
769ANSWERS
(b) BD DCAD BCbisects
(corresponding sides in congruent s)`
`
D=
4. , )AB CDABD BDC ernate angles+ + <= (alt
( , )ADB DBCBD
ABD CDBAD BC
AD BCis common
by AAS,
alternate angles
(corresponding sides in congruent s)
`
`
+ +
/
<
D D
D
=
=
5. (a) OA OC= (equal radii)
OB OD= (similarly)
AOB COD+ += (vertically opposite angles)
AOB COD` /D D ( SAS )
(b) AB CD= (corresponding sides in congruent
triangles)
6. (a) AB AD= (given)
BC DC= (given)
AC is common
ABC ADC` /D D ( SSS )
(b) ABC ADC+ += (corresponding angles in congruent
triangles)
7. (a) OA OC= (equal radii)
OB is common
AOB COB 90c+ += = (given)
OAB OBC` /D D ( SAS )
(b) OCB OBC+ += (base angles of OBC, an isosceles
right angled triangle)
But OCB OBC 90c+ ++ = (angle sum of triangle)
So OCB OBC 45c+ += =
Similarly 45OBA c+ =
45 45 90OBA OBC` c c c+ ++ = + =
So ABC+ is right angled
8. (a) 90AEF BDC c+ += = (given)
AF BC= (given)
FE CD= (given)
AFE BCD` /D D ( RHS )
(b) AFE BCD+ += (corresponding angles in
congruent triangles)
9. (a) OA OC= (equal radii)
OB is common
AB BC= (given)
OAB OBC` /D D ( SSS )
(b) OBA OBC+ += (corresponding angles in
congruent triangles)
But 180OBA OBC c+ ++ = ( ABC is a straight angle)
So 90OBA OBC c+ += =
OB is perpendicular to AC.
10. (a) AD BC= (given)
ADC BCD 90c+ += = (given) DC is common ADC BCD` /D D ( SAS )
(b) AC BD= (corresponding sides in congruent
triangles)
Exercises 4.5
1. (a) .x 15 1= (b) 4.4x = (c) 6.6m =
(d) , ,76 23 81c c ca i b= = = (e) 4.5b =
(f) , , .x y115 19 3 2c ca = = = (g) 9.7p =
2. . , .a b1 81 5 83= =
3. ( , )
( )
BAC EDCABC DECACB ECD
AB EDalternate angles(similarly)vertically opposite angles
+ ++ ++ +
<=
=
=
since 3 pairs of angles are equal, | CDED||ABCD
4.
.
..
..
.
GFE EFD
EFGF
DFEF
EFGF
DFEF
2 71 5
0 5
4 862 7
0 5
(given)
`
+ +=
= =
= =
=
o
o
Since two pairs of sides are in proportion and their included angles are equal, then | FGED||DEFD
5. ..
.
..
.
..
.
DEAB
DFAC
EFBC
DEAB
DFAC
EFBC
1 821 3
0 714
5 884 2
0 714
6 864 9
0 714
`
= =
= =
= =
= =
Since three pairs of sides are in proportion, | DEFD||ABCD
y 41c=
6. (a) OA OBOC OD
ODOA
OCOB
AOB COD
(equal radii)(similarly)
(vertically opposite angles)
`
+ +
=
=
=
=
Since two pairs of sides are in proportion and their included angles are equal, | OCD3||OAB3
(b) 5.21AB cm=
7. (a) A+ is common
( , )ABC ADE
ACB AEDBC DEcorresponding angles
(similarly)+ ++ +
<=
=
Answer S1-S5.indd 769 8/2/09 2:47:58 AM
770 Maths In Focus Mathematics Extension 1 Preliminary Course
since 3 pairs of angles are equal, | ADED||ABCD
(b) . , .x y2 17 2 25= =
8. ( , )( , )( )
ABF BECCBE BFA
C A
s AB CDBC AD
s
alternate anglesimilarlyangle sum of`
+ ++ ++ +
z
z
D
=
=
=
since 3 pairs of angles are equal, | CEBD||ABFD
9. A+ is common
..
..
ABAD
ACAE
ABAD
ACAE
31 2
0 4
20 8
0 4
`
= =
= =
=
Since two pairs of sides are in proportion and their included angles are equal, | , .ABC m 4 25D =||AEDD
10. .
.
..
..
.
CDAB
ACBC
ADAC
CDAB
ACBC
ADAC
2 62
0 769
3 93
0 769
5 073 9
0 769
`
= =
= =
= =
= =
Since three pairs of sides are in proportion,
,c| ,ACD x y109 47cD = =||ABCD
11. (a) 7.8x = (b) . , .m p4 0 7 2= = (c) 6.5x =
(d) . , .x y6 2 4 4= = (e) . , .x y1 4 9 2= =
12. (a) BCAB
DEAD
DEAD
FGAF
BCAB
FGAF
Also
`
=
=
=
(b)ACAB
AEAD
AEAD
AGAF
ACAB
AGAF
Also
`
=
=
=
(c) CEBD
AEAD
AEAD
EGDF
CEBD
EGDF
Also
`
=
=
=
13. . , .a b4 8 6 9= = 14. 0.98y = 15. . , .x y3 19 1 64= =
Exercises 4.6
1. (a) 6.4x = (b) 6.6y = (c) 5.7b = (d) 6.6m =
2. (a) 61p = (b) 58t = (c) 65x = (d) 33y =
3. .s 6 2 m= 4. .CE 15 3 cm=
5. 81, 144, 225AB CB CA2 2 2= = =
AB CB
CA
81 144225
2 2
2
+ = +
=
=
ABC` D is right angled
6. 1XY YZ= = XYZ` D is isosceles
,YZ XY XZYZ XY
XZ
1 21 12
2 2 2
2 2
2
= = =
+ = +
=
=
XYZ` D is right angled
7. AC AB BC
BCBC
BCBC
AC
BC
2 34 311
22 12
2 2 2
2 2 2
2
2
`
#
= +
= +
= +
=
=
=
=
=
^ h
8. (a) 5AC =
(b) , ,AC CDAD
25 144169
2 2
2
= =
=
25 144169
AC CD
AD
2 2
2
+ = +
=
=
ACD` D has a right angle at ACD+ AC` is perpendicular to DC
9. AB b3= 10. xx y2 2+
11. d t tt t t t
t t
20 3 15 2400 120 9 225 60 413 180 625
2 2 2
2 2
2
= - + -
= - + + - +
= - +
] ]g g
12. 1471 mm 13. 683 m 14. 12.6 m 15. 134.6 cm
16. 4.3 m 17. 42.7 cm
18. 1.3 1.1 2.9 1.5 2.25and2 2 2+ = =
. . .1 3 1 1 1 52 2 2!+ so the triangle is not right angled the property is not a rectangle
19. No. The diagonal of the boot is the longest available space and it is only 1.4 m.
20. (a) 6 4BC2 2 2= - 20= 20BC = 6AO cm= (equal radii) So 6 4AC2 2 2= - 20= 20AC = Since ,BC AC= OC bisects AB
(b) OCA OCB 90c+ += = (given) OA OB= (equal radii) OC is common OAC OBC` /D D ( RHS ) So AC BC= (corresponding sides in congruent triangles) OC bisects AB
Exercises 4.7
1. (a) x 94c= (b) y 104c= (c) x 111c= (d) x 60c= (e) y 72c= (f) °, °x y102 51= = (g) °, °x y43 47= =
Answer S1-S5.indd 770 7/11/09 1:26:31 AM
771ANSWERS
2. ABED is isosceles.
( s )
( )
B ECBE DEB
76180 76104
base equal
straight s
` cc cc
+ ++ +
+
+
= =
= = -
=
D
DD
62 104 104 360270 360
90
(angle sum of quadrilateral)c c c cc c
c
++
+
+ + + =
+ =
=
CD is perpendicular to AD
3. (a)
( )( , )
( , )
( , )
D x
C x
xx
A C xB xB D x
A D AB DC
C D AD BC
B C AB DC
180
180 180
180 180
180180
and cointerior angles
and cointerior angles
and cointerior angles`
`
c
c c
c c
cc
+
+
+ +++ +
+ +
+ +
+ +
<
<
<
= -
= - -
= - +
=
= =
= -
= = -
(b) x x x x180 180360
Angle sum c cc
= + + - + -
=
4. ,a b150 74c c= =
5. (a) 5 , 3 , 108 , 72a b x z ym m c c= = = = = (b) , ,x y z53 56 71c c c= = = (c) 5 , 68x y cm ca b= = = = (d) , ,121 52 77c c ca b i= = = (e) 60x c= (f) ,x y3 7= =
6. ( ), ),
ADB CDBCDB ABDADB DBCABD DBC
BD ABC
BD ADCAB DCAD BC
bisects
bisects(alternate angles(alternate angles )
`
`
+ ++ ++ ++ +
+
+
<
<
=
=
=
=
7. (a) ..
AD BCAB DC
3 85 3
cmcm
(given)(given)
= =
= =
Since two pairs of opposite sides are equal, ABCD is a parallelogram.
(b) AB DCAB DC
7cm (given)
(given)<
= =
Since one pair of opposite sides is both equal and parallel, ABCD is a parallelogram.
(c) 54 126180
X M c cc
+ ++ = +
=
These are supplementary cointerior angles. XY MN` <
XM YNAlso, (given)<
XMNY is a parallelogram
(d) AE ECDE EB
56
cmcm
(given)(given)
= =
= =
Since the diagonals bisect each other, ABCD is a parallelogram.
8. (a) ,x 5 66cm ci= = (b) , ,90 25 65c c ca b c= = = (c) ,x y3 5cm cm= = (d) ,x y58 39c c= = (e) x 12 cm=
9. 6.4 cm 10. 59 , 31 , 59ECB EDC ADEc c c+ + += = =
11. 4 2 cm 12. 57x y c= =
Exercises 4.8
1. (a) 540c (b) 720c (c) 1080c (d) 1440c (e) 1800c (f) 2880c 2. (a) 108c (b) 135c (c) 150c (d) 162c (e) 156c 3. (a) 60c (b) 36c (c) 45c (d) 24c
4. 128 34c l 5. (a) 13 (b) 152 18c l 6. 16 7. 3240c
8. 2340c 9. 168 23c l
10. ( )
.
n nn n
nn
145145 180 360
3510 3
2 180Sum # c= = -
= -
=
=
But n must be a positive integer. no polygon has interior angles of 145 .c
11. (a) 9 (b) 12 (c) 8 (d) 10 (e) 30
12. (a) ABCDEF is a regular hexagon. AF BC= (equal sides) FE CD= (equal sides) AFE BCD+ += (equal interior angles) AFE BCD` /D D ( SAS )
(b) ( )
S n
AFE
6720
6720
120
2 1802 180#
#
cc
cc
c
+
= -
= -
=
=
=
] g
Since ,AF FE= triangle AFE is isosceles. So FEA FAE+ += (base angles in isosceles triangle)
FEA2
180 120
30
`c
c
+ =-
=
(angle sum of triangle)
EDA 120 3090
cc
+ = -
=
Similarly, DEB 90c+ =
So ED DEA B 180c+ ++ = These are supplementary cointerior angles AE BD` <
13. A regular octagon has equal sides and angles. AH AB= (equal sides)
GH BC= (equal sides) AHG ABC+ += (equal interior angles)
AHG ABC` /D D ( SAS )
So AG AC= (corresponding sides in congruent triangles)
( )S n
81080
2 1802 180#
#
cc
c
= -
= -
=
] g
AHG
81080
135
`c
c
+ =
=
HGA HAG+ += (base angles in isosceles triangle)
Answer S1-S5.indd 771 8/2/09 2:47:59 AM
772 Maths In Focus Mathematics Extension 1 Preliminary Course
HAG2
180 135
22 30
`c
c
+ =-
= l
(angle sum of triangle)
GAC 135 2 22 30
90# c
c+ = -
=
l
We can similarly prove all interior angles are 90c and adjacent sides equal . So ACEG is a square .
14. EDC5
5
108
2 180# c
c
+ =-
=
] g
ED CD= (equal sides in regular pentagon)
So EDC is an isosceles triangle. DEC ECD`+ += (base angles in isosceles triangle)
36
DEC2
180 108c
c
+ =-
=
(angle sum of triangle)
108 3672
AEC cc
+ = -
=
Similarly, using triangle ABC , we can prove that 72EAC c+ = So EAC is an isosceles triangle. (Alternatively you could prove EDC and ABC congruent triangles and then AC EC= are corresponding sides in congruent triangles.)
15. (a) p
360
(b) Each interior angle:
180360
180 360
180 360
180 2
p
p
p
p
p
p
p
p
-
= -
=-
=-^ h
Exercises 4.9
1. (a) .26 35 m2 (b) .21 855 cm2 (c) .18 75 mm2 (d) 45 m2 (e) 57 cm2 (f) 81 m2 (g) .28 27 cm2 2. .4 83 m2
3. (a) .42 88 cm2 (b) .29 5 m2 (c) .32 5 cm2 (d) .14 32 m2 (e) .100 53 cm2 4. (a) 25 m2 (b) .101 85 cm2 (c) .29 4 m2 (d) .10 39 cm2 (e) 45 cm2
5. 7 51 98 7 51 14 cm2+ = +^ h 6. .22 97 cm2
7. $621.08 8. (a) .161 665 m2 (b) 89 m2 (c) 10.5 m
9. (a) 48 cm (b) 27 cm 10. w12 units2
Test yourself 4
1. (a) , ,x y z43 137 147c c c= = = (b) 36x c= (c) , ,a b c79 101 48c c c= = = (d) 120x c= (e) 7.2r cm= (f) 5.6 , 8.5x ycm cm= = (g) 45ci =
2. )AGF HGB(vertically opposite+ +i=
AGF CFESo+ + i= =
These are equal corresponding .s+ AB CD` <
3. 118.28 cm 2
4. (a)
( )
DAE BACADE ABCAED ACB
ABC ADE AAAand are similar
(common)(corresponding angles, DE BC)(similarly)
`
+ ++ ++ +
<
D D
=
=
=
(b) 3.1 , 5.2x ycm cm= =
5. 162c 6. 1020.7 cm 3 7. 36 m
8. (a) AB ADBC DC
(adjacent sides in kite)(similarly)
=
=
AC is common Δ ABC and Δ ADC are congruent (SSS)
(b) AO COBO DO
AOB COD
(equal radii)(similarly)(vertically opposite angles)+ +
=
=
=
Δ AOB and Δ COD are congruent (SAS)
9. 73.5 cm 2
10. 6 2 7 36 28 64 82 2 2+ = + = =^ h ` Δ ABC is right angled (Pythagoras)
11. AGAF
AEAD
AEAD
ACAB
AGAF
ACAB
(equal ratios on intercepts)
(similarly)
`
=
=
=
12. (a) (base s of isosceles+ D)( , )
AB ACB C
BD DC AD BC
(given)
bisects given+ +
=
=
=
ABD ACD SAS` /D D ] g (b)
180ADB ADC
ADB ADCBut(corresponding s in congruent s)
(straight )c+ ++ +
+
+
D=
+ =
So 90ADB ADC c+ += =
So AD and BC are perpendicular.
13.
34˚ 34
( )( )
ACBCAD
CAD ADC
6868 34
base s of isoscelesexterior of
`
cc cc
c
++
+ +
+
+
D
D
=
= -
=
= =
So Δ ACD is isosceles base s equal+^ h 14.
Answer S1-S5.indd 772 7/11/09 1:26:32 AM
773ANSWERS
( , )
, )DAC ACBBAC ACD
AD BCs AB DC
alternate s(alternate
+ ++ +
+
+
<
<
=
=
AC is common
ABC ADC
AB DC(AAS)
(corresponding sides in congruent s)`
`
/D D
D=
Similarly, AD BC= opposite sides are equal
15. (a) 24 cm 2 (b) 5 cm 16. 9
17. BFG FGD x x109 3 3 71180c cc
+ ++ = - + +
=
These are supplementary cointerior .s+ AB CD` <
18. 57 cm 2
19. (
(( )
)
)
ACB A Bx y
ACD ACBz x y
x yx y
180180180180 180180 180
sum of
straight
cccc cc c
+ + +
+ +
+
+
D= - +
= - -
= -
= - - -
= - + +
= +
] g
20. (a)
..
.
..
.
A E
EFAC
DEAB
EFAC
DEAB
2 72 97
1 1
3 63 96
1 1
given
`
+ +=
= =
= =
=
^ h
So Δ ABC and Δ DEF are similar (two sides in proportion, included s+ equal). (b) 4.3x cm=
Challenge exercise 4
1. 94c 2. , ,x y z75 46 29c c c= = = 3. ,1620 32 44c c l
4. , )
( )
BAD DBCABD BDCADB DCB
AB DC(given)(alternate anglesangle sum of`
+ ++ ++ +
<
D
=
=
=
since 3 pairs of angles are equal, BCDD;ABD <D
6.74d cm=
5. AB DCA D 131 49
180
(given)c cc
+ +=
+ = +
=
A+ and D+ are supplementary cointerior angles AB DC` <
Since one pair of opposite sides are both parallel and equal, ABCD is a parallelogram.
6. .27 36 m2
7.
Let ABCD be a square with diagonals AC and BD and
D
AD DC90
(adjacent sides of square)c+ =
=
°
°°
ADCDAC DCA
DAC DCADAC DCABAC BCA
904545
is isosceles
Similarly,
(base angles of isosceles )(angle sum of )
(other angles can be proved similarly)
`
`
`
+ ++ +
+ ++ +
D
D
D
=
+ =
= =
= =
8.
Let ABCD be a kite
AD ABDC BC
(given)(given)
=
=
AC is common
, ADC ABCDAC BAC
AD ABDAE BAE
by SSS
(corresponding angles in congruent s)(given)(found)
`
` + +
+ +
/D D
D
=
=
=
AE is common
,(
( )
ADE ABEDEA BEADEA BEADEA BEA
DEB18090
by SAS
But
the diagonals are perpendicular
corresponding angles in congruent s)is a straight angle
`
`
`
`
cc
+ ++ ++ +
/D D
D=
+ =
= =
9. 84 (15 112 ) )
( )
MNYMNY
XYZXYZMNY XYZ
MNZ
XYZ43
69 11243
43
(exterior angle of
exterior angle of`
`
`
c c cc
c cc
c
++
+++ +
D
D
+ = +
=
+ =
=
= =
These are equal corresponding angles. MN XY` <
10. .x 2 12 m= 11. (a) 6 m2 (b) 10 2 5 2 5 5 m+ = +^ h
12. . , .x y28 7 3 8cm cm== 13. 7.40 , 4.19x ym m= =
Answer S1-S5.indd 773 8/2/09 2:48:00 AM
774 Maths In Focus Mathematics Extension 1 Preliminary Course
14. (a) AB BCABE CBE 45
(adjacent sides in square)
(diagonals in square make 45 with sides)c
+ +=
= =
EB is common.
, ABE CBE
AE CEby SAS
(corresponding sides in congruent s)`
`
/D D
D=
Since AB BC= and ,AE CE= ABCE is a kite.
(b) BD x x
xx
DE BD
x
22
21
22
units
2 2
2
= +
=
=
=
=
Practice assessment task set 1
1. 9p = 2. 2 5 y x y+ -^ ^h h 3. (a) x 1- (b) 3x4
4. 6 10y - 5. 23
25 5 2+ 6. 2 16 3x x x3 2+ - +
7. 72
x = 8. 3
2x -
9. °ABC EDCACB ECD
AB EDABC EDC
AC ECACE
90
by AAS
is isosceles
(given)(vertically opposite angles)(given)
(corresponding sides in congruent triangles)`
`
`
+ ++ +
/D D
D
= =
=
=
=
10. 231.3 11. 3- 12. 135c 13. 7.33 10 2#
-
14. 3 10 4- 15. 3.04 16. 3x + 17. . , .x 1 78 0 281= -
18. 1.55r = 19. x 12
20. 157
21. x2
42 3
12!!= = 22.
491
23. 4, 11 1, 4x y x yor= = = - = - 24. ,x y2 1= = -
25. 7 26. 7.02 cm 27. 2 1 4 2 1x x x2- + +] ^g h
28. 43
6 15 2 6+ 29. 7 30. $643.08 31. 1.1
32. 2 10 3 5 2 2 3- + - + 33. $83.57
34. , ,x y w z22 29 90c c c= = = = 35. 56.7 cm2
36. a ba
b21 10
21
10
=- 37. ,x x6 252
2 1 - 38. 81
39. x 7- - 40. 41
x = 41. ,x x3 3# $- 42. 61
43. Given diagonal AC in rhombus ABCD :
)
)
AB BCDAC ACBBAC ACBDAC BAC
AD BCABC
(adjacent sides in rhombus)(alternate s,(base s of isosceles
`
+ ++ ++ +
+
+
<
D
=
=
=
=
` diagonal AC bisects the angle it meets. Similarly, diagonal BD bisects the angle it meets.
44. x 3 1+ -] g 45. 6 12 8x x x3 2+ + + 46. 2
517
4
47. 53x c=
48. ,x y98 41c c= = 49. x0 51 1 50. 3 2
1
x +
51. (a) 12 8x y- (b) 2 31 (c) 3 9
3
x x
x2 - +
- (d) 3 2 1+
(e) 1 1
5
x x
x
+ -
- +
] ]]g g
g (f)
611 3
(g) x y zx z
y14 7 11
14 11
7
=- -
(h) 5 1 2
3a a b b+ +] ]g g (i) 8 5 (j) 13
21
52. . , .x y2 7 3 1= = 53. 25x = 54. r2
cm3 r
=
55. 17.3 cm
56. DEA xEAD xCD x x
xABC xABC DEA
A222
LetThen (base s of isosceles )
(exterior of )
(opposite s of gram are equal)
EAD
`
`
+++
++ +
+
+
+ <
D
D
=
=
= +
=
=
=
57. 52
58. 5% 59. 2.2 10 kmh8 1#
- 60. 20k =
61. 9xy y 62. 147 16c l 63. 5.57 m2
64. (a) a b a a ab b b5 2 2 4 2 4 4 42 2+ - - - + + +] ^g h (b) 3 4 6 2a b a b c+ - +] ]g g
65. x181
543
1#-
66. (BCEF is a gram)<
(BC AD ABCDBC FEAD FE
is a gram)
`
< <
<
<
BC ADBC FEAD FE
Also opposite sides of gram
similarly`
<=
=
=
^^
hh
Since AD and FE are both parallel and equal, AFED is a parallelogram.
67. 11.95b m= 68. (a) 34 cm (b) 30 cm 2
Answer S1-S5.indd 774 7/11/09 1:26:34 AM
775ANSWERS
69. 75
18 3 31 2 25 5+ - 70. 20 71. 32 m
72. BD bisects AC So AD DC= 90BDC BDA c+ += = (given) BD is common BAD BCD` /D D ( SAS ) AB CB` = (corresponding sides in congruent
triangles) So triangle ABC is isosceles
73. 2
x y2 2+ 74. (b) 75. (c) 76. (a) 77. (b) 78. (b)
79. (d) 80. (d)
Chapter 5 : Functions and graphs
Exercises 5.1
1. Yes 2. No 3. No 4. Yes 5. Yes 6. Yes 7. No
8. Yes 9. Yes 10. No 11. Yes 12. No 13. Yes
14. No 15. Yes
Exercises 5.2
1. 4, 0f f1 3= - =] ]g g 2. , ,h h h0 2 2 2 4 14= - = - =] ] ]g g g
3. 25, 1, 9, 4f f f f5 1 3 2= - - = - = - - = -] ] ] ]g g g g 4. 14
5. 35- 6. 9x = 7. x 5!= 8. x 3= - 9. ,z 1 4= -
10. 2 9, 2 2 9f p p f x h x h= - + = + -^ ]h g
11. 1 2g x x2- = +] g 12. f k k k k1 12= - + +] ] ^g g h 13. ; ,t t1 2 4= - = - 14. 0
15. 125, 1, 1f f f5 1 1= = - = -] ] ]g g g
16. 0 4 1 3f f f2 2 1- - + - = - + = -] ] ]g g g
17. 10 18. 7 19. 28-
20. (a) 3 (b) 3 3 3 0x - = - = Denominator cannot be 0 so the function doesn’t exist for .x 3= (c) 4
21. 2 5f x h f x xh h h2+ - = + -] ]g g 22. 4 2 1x h+ +
23. x c5 -] g 24. 3 5k2 + 25. (a) 2 (b) 0 (c) 2n n4 2+ +
Exercises 5.3
1. (a) x -intercept 32
, y -intercept -2
(b) x -intercept -10, y -intercept 4 (c) x -intercept 12, y -intercept 4 (d) x -intercepts 0, -3, y -intercept 0 (e) x -intercepts 2! , y -intercept -4 (f) x -intercepts -2, -3, y -intercept 6
(g) x -intercepts 3, 5, y -intercept 15
(h) x -intercept 53- , y -intercept 5 (i) x -intercept -3, no y -intercept (j) x -intercept ,3! y -intercept 9
2. 2
( )
f x xxf x
2
even function
2
`
- = - -
= -
=
2] ]g g
3. (a) 1f x x2 6= +^ h (b) f x x x2 12 6 3= + +] g7 A
(c) 1f x x3- = - +] g (d) Neither odd nor even
4.
( )
g x x x xx x xg x
3 23 2
even function
8 4 2
8 4 2
`
- = - + - - -
= + -
=
] ] ] ]g g g g
5. f x x f x- = - = -] ]g g odd function
6. 1
( )
f x xxf x
1
even function
2
2
`
- = - -
= -
=
] ]g g
7. f x x xx xx x
f x
444
odd function
3
3
3
`
- = - - -
= - +
= - -
= -
] ] ]^]
g g gh
g
8. f x x xx xf x
even function
4 2
4 2
`
- = - + -
= +
=
] ] ]]
g g gg
0f x f x- - =] ]g g
9. (a) Odd (b) Neither (c) Even (d) Neither (e) Neither
10. (a) Even values i.e. , , ,n 2 4 6 f=
(b) Odd values i.e. , , ,n 1 3 5 f=
11. (a) No value of n (b) Yes, when n is odd (1, 3, 5, …)
12. (a) (i) x 02 (ii) x 01 (iii) Even
(b) (i) x 21 (ii) x 22 (iii) Neither
(c) (i) x2 21 1- (ii) ,x x2 21 2- (iii) Neither
(d) (i) All real x 0! (ii) None (iii) Odd
(e) (i) None (ii) All real x (iii) Neither
Exercises 5.4
1. (a) x -intercept 2, y -intercept -2
(b) x -intercept 121
- , y -intercept 3
(c) x -intercept 21
, y -intercept 1
(d) x -intercept -3, y -intercept 3
(e) x -intercept 32
, y -intercept 31
-
Answer S1-S5.indd 775 7/11/09 1:26:34 AM
776 Maths In Focus Mathematics Extension 1 Preliminary Course
2. (a)
-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
(b) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
(c) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
(d) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2-1
1
(e) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2-1
112
(f) y
x-4
-5
-3 -2-1 2 3 4
2
1
3
4
5
-3
-4
-2-1
1
(g) y
x-4
-5
-3-2 -1 2 3 4
2
1
3
4
5
-3
-4
-2-1
1
23
-
(h) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
Answer S1-S5.indd 776 7/11/09 1:26:35 AM
777ANSWERS
(i) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
(j) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-1111
2
3. (a) ,x yall real all real" ", , (b) :,x y y 2all real =" ", , (c) : ,x x y4 all real= -! "+ , (d) : ,x x y2 all real=! "+ , (e) , :x y y 3all real =! "+ ,
4. (a) Neither (b) Even (c) Neither (d) Odd (e) Odd
5. y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-1111
2
(3, -1)
Exercises 5.5
1. (a) x -intercepts 0, -2, y -intercept 0 (b) x -intercepts 0, 3, y -intercept 0 (c) x -intercepts ! 1, y -intercept -1 (d) x -intercepts -1, 2, y -intercept -2 (e) x -intercepts 1, 8, y -intercept 8
2. (a) y
x-4
-5
-3 -2-1 2 3 4 5
2
1
3
4
5
6
-3-4
-2-1
1
(b) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
6
-3
-4
-2
-11
(c) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
6
-3
-4
-2-1
1
Answer S1-S5.indd 777 7/11/09 1:26:36 AM
778 Maths In Focus Mathematics Extension 1 Preliminary Course
(d) y
x-4
-5
-3 -2-1 2 3 4 5
2
1
3
4
5
6
-3
-4
-2
-1 1
(e) y
x-4
-5
-3 -2-1 2 3 4 5
21
3
4
5
6
-3
-4
-2
-11
(f) y
x-4
-10
-3 -2 -1 2 3 4 5
4
6
8
2
10
12
-6
-8
-4-2
1
(g) y
x-4
-5
-3 -2 -1 2 3 4 5
21
3
4
5
-3
-4
-6
-2
-11
(h) y
x
-5
-3-4 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-6
-2
-1 1
(i) y
x-4
-5
-3 -2 -1 3 4 5
2
1
3
4
5
-3
-4
-6
-2-1 2111
2
(j) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3-4
-6
-2-1
1
3. (a) (i) x -intercepts 3, 4, y -intercept 12 (ii) {all real x },
:y y41
$ -( 2 (b) (i) x -intercepts 0, -4, y -intercept 0 (ii) {all real x }, :y y 4$ -" , (c) (i) x -intercepts -2, 4, y -intercept -8 (ii) {all real x }, : 9y y $ -" , (d) (i) x -intercept 3, y -intercept 9 (ii) {all real x }, :y y 0$" , (e) (i) x -intercepts ,2! y -intercept 4 (ii) {all real x }, :y y 4#" ,
4. (a) {all real x }, :y y 5$ -" , (b) {all real x }, :y y 9$ -" ,
Answer S1-S5.indd 778 7/11/09 1:26:37 AM
779ANSWERS
(c) {all real x }, :y y 241
$ -( 2 (d) {all real x }, :y y 0#" , (e) {all real x }, : 0y y $" ,
5. (a) y0 9# # (b) y0 4# # (c) y1 24# #-
(d) y4 21# #- (e) y18 241
# #-
6. (a) (i) x 02 (ii) x 01 (b) (i) x 01 (ii) x 02
(c) (i) x 02 (ii) x 01 (d) (i) x 21 (ii) x 22 (e) (i) x 52 - (ii) x 51 -
7.
( )
f x xx
f xeven
2
2
`
- = - -
= -
=
] ]g g
8. (a) Even (b) Even (c) Even (d) Neither (e) Neither (f) Even (g) Neither (h) Neither (i) Neither (j) Neither
Exercises 5.6
1. (a) x -intercept 0, y -intercept 0 (b) No x -intercepts, y -intercept 7 (c) x -intercepts ,2! y -intercept -2 (d) x -intercept 0, y -intercept 0 (e) x -intercepts ,3! y -intercept 3 (f) x -intercept -6, y -intercept 6
(g) x -intercept 32
, y -intercept 2
(h) x -intercept 54
- , y -intercept 4
(i) x -intercept 71
, y -intercept 1
(j) No x -intercepts, y -intercept 9
2. (a) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(b) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(c) y
-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(d) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(e) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(f) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
Answer S1-S5.indd 779 7/13/09 10:16:03 AM
780 Maths In Focus Mathematics Extension 1 Preliminary Course
(g) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(h) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(i) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(j) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
3. (a) {all real x }, :y y 0$" , (b) {all real x }, :y y 8$ -" , (c) {all real x }, :y y 0$" , (d) {all real x }, :y y 3$ -" , (e) {all real x }, :y y 0#" ,
4. (a) (i) x 22 (ii) x 21 (b) (i) x 02 (ii) x 01
(c) (i) x 121
2 (ii) x 121
1 (d) (i) x 02 (ii) x 01
(e) (i) x 01 (ii) x 02
5. (a) 0 2y# # (b) y8 4# #- - (c) 0 6y# #
(d) 0 11y# # (e) y1 0# #-
6. (a) x 32 - (b) x 01 (c) x 92 (d) x 22 (e) x 21 -
7. (a) x 3!= (b) ,x x1 12 1 - (c) x2 2# #-
(d) ,x 1 3= - - (e) 3x = (f) ,x 1 2= (g) x3 51 1-
(h) x4 2# #- (i) ,x x4 02 1 (j) ,x x2 4# $
(k) x4 1# #- (l) ,x x0 1# $ (m) ,x 221
= -
(n) No solutions (o) 0x = (p) 1x = (q) ,x 0 2= -
(r) No solutions (s) 31
x = ( t) 0, 6x =
Exercises 5.7
1. (a) (i) {all real x : x ! 0}, {all real y : y ! 0} (ii) no y -intercept
(iii) y
x-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
(b) (i) {all real : },x x 0! {all real :y y 0! } (ii) no y -intercept
(iii) y
x-2 -1 2
2
1
-2
-1
1
Answer S1-S5.indd 780 7/12/09 2:04:41 AM
781ANSWERS
(c) (i) {all real :x x 1! - }, {all real : 0y y ! } (ii) 1
(iii) y
x-2 -1 2
2
1
-2
-1
1
(d) (i) {all real :x x 2! }, {all real : 0y y ! } (ii) 121
-
(iii) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(e) (i) {all real :x x 2! - }, {all real : 0y y ! } (ii) 61
(iii) y
x-2 -1 2
2
1
-2
-1
1
(f) (i) {all real :x x 3! }, {all real :y y 0! } (ii) 32
(iii) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(g) (i) {all real : 1x x ! }, {all real : 0y y ! } (ii) -4
(iii) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
(h) (i) {all real : 1x x ! - }, {all real : 0y y ! } (ii) -2
(iii) y
x-4
-5
-3 -2-1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
Answer S1-S5.indd 781 7/11/09 1:26:40 AM
782 Maths In Focus Mathematics Extension 1 Preliminary Course
(i) (i) :21
x xall real !' 1 , {all real : 0y y ! } (ii) 32
-
(iii) y
x-2 -1 2
2
1
-2
-1
1
23
-
12
(j) (i) {all real :x x 2! - }, {all real :y y 0! } (ii) -3
(iii) y
x-4
-5
-3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-2
-11
2.
( )
f x x
xf x
2
2
odd function`
- =-
= -
= -
] g
3. (a) 1y91
## (b) 1y31# # (c) y2
21
21
# #- -
(d) 3y73
## (e) 2 y81
# #- -
4. (a) 1 3x# # (b) 1 4x# # (c) 6 0x# #-
(d) 1 4x# # (e) 1 2x# #
Exercises 5.8
1. (a) (i) y
x-3
3
3
-3
(ii) : , :x x y y3 3 3 3# # # #- -! "+ , (b) (i) y
x-4
4
4
-4
(ii) : , :x x y y4 4 4 4# # # #- -! "+ , (c) (i)
(2, 1)
-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
y
x
Answer S1-S5.indd 782 7/11/09 1:26:41 AM
783ANSWERS
(ii) : 0 4 , : 1 3x x y y# # ## -! "+ , (d) (i)
-4
-5
-3 -2 -1 2 3 4
2
1
3
4
5
-3
-4
-2
-11
y
x
(ii) : , :x x y y4 2 3 3# # # #- -! "+ , (e) (i)
-4 -3 -2 -1 2 3 4
2
1
3
4
5
-2
-1
(-2, 1)
1
y
x
(ii) : , :x x y y3 1 0 2# # # #- -! "+ , 2. (a) (i) Below x -axis
(ii) y
x-5 5
-5
(iii) : , :x x y y5 5 5 0# # # #- -! "+ , (b) (i) Above x -axis
(ii) y
x-1
1
1
(iii) : , :x x y y1 1 0 1# # # #-! "+ , (c) (i) Above x -axis
(ii) y
x-6
6
6
(iii) : , :x x y y6 6 0 6# # # #-! "+ , (d) (i) Below x -axis
(ii) y
x-8 8
-8
(iii) : , :x x y y8 8 8 0# # # #- -! "+ ,
Answer S1-S5.indd 783 7/11/09 1:26:42 AM
784 Maths In Focus Mathematics Extension 1 Preliminary Course
(e) (i) Below x -axis
(ii) y
x- 7
- 7
7
(iii) : , :x x y y7 7 7 0# # # #- -" #, - 3. (a) Radius 10, centre (0, 0) (b) Radius 5 , centre (0, 0)
(c) Radius 4, centre (4, 5) (d) Radius 7, centre (5, -6) (e) Radius 9, centre (0, 3)
4. (a) 16x y2 2+ =
(b) 6 4 12 0x x y y2 2- + - - =
(c) 2 10 17 0x x y y2 2+ + - + =
(d) 4 6 23 0x x y y2 2- + - - =
(e) 8 4 5 0x x y y2 2+ + - - =
(f) 4 3 0x y y2 2+ + + =
(g) 8 4 29 0x x y y2 2- + - - =
(h) 6 8 56 0x x y y2 2+ + + - =
(i) 4 1 0x x y2 2+ + - =
(j) 8 14 62 0x x y y2 2+ + + + =
Exercises 5.9
1. (a) {all real x }, {all real y } (b) {all real x }, {y: y = -4} (c) {x: x = 3}, {all real y } (d) {all real x }, { y : y $ -1 }
(e) {all real x }, {all real y } (f) {all real x }, : 1241
y y #' 1 (g) { : 8 8}, { : 8 8}x x y y# # # #- -
(h) {all real :t t 4! }, {all real ( ): ( )f t f t 0! }
(i) {all real : 0!z z }, {all real :g g 5!zz^ ^h h }
(j) {all real x }, { :y y 0$ }
2. (a) { x : 0x $ }, { y : y 0$ } (b) { x : x 2$ }, { y : y 0$ } (c) {all real x }, { y : y 0$ } (d) {all real x }, { y : y 2$ - }
(e) : 221
, { : }x x y y 0$ #-' 1
(f) {all real x }, { :y y 5# } (g) {all real x }, { : }y y 02
(h) {all real x }, { : }y y 01
(i) {all real :x x 0! }, {all real :y y 1! } (j) {all real :x x 0! }, {all real :y y 2! }
3. (a) ,x 0 5= (b) , ,x 3 1 2= - (c) , ,x 0 2 4=
(d) ,x 0 4!= (e) x 7!= 4. (a) x1 1# #-
(b) { : }x x1 1# #-
5. (a) { : , }x x x1 2# $- (b) { : , }t t t6 0# $-
6. (a) { y : y9 3# #- }
(b) { y : y0 9# # } (c) { y : y8 1# #- }
(d) :51
1y y# #' 1 (e) { y : 0 4y# # }
(f) { y : y1 15# #- } (g) { y : y1 0# #- }
(h) :y y1 8# #-" , (i) { y : 4 21y# #- }
(j) :y y61
64
# #-' 1 7. (a) {all real :x x 1! - }
(b) x -intercept: 0y =
01
3x
=+
0 3= This is impossible so there is no x -intercept (c) {all real :y y 0! }
8. (a) {all real :x x 0! } (b) {all real :y y 1!! }
9. (a) y
x-4 -3 -2 -1 2 3 4 5
10
5
15
20
25
-15
-10
-51
(b) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-8
-4
-21
(c) y
x-4 -3 -2 -1 2 3 4 5
10
5
15
20
25
-15
-10
-51
Answer S1-S5.indd 784 7/11/09 1:26:43 AM
785ANSWERS
(d) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-8
-4
-21
(e) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-8
-4
-21
(f) y
x-10 10
10
-10
(g) y
x-1
1
2
3
-1
1
10. (a) : : 0x x y y1$ $" ", , (b) y
x2 3
2
1
-11
11. y
x-1
4
3
2
1
5
6
-1 1
12. (a) (i) {all real x }, {all real y } (ii) All x (iii) None (b) (i) {all real x }, :y y 22 -" , (ii) x 02 (iii) x 01 (c) (i) {all real :x x 0! }, {all real : 0y y ! } (ii) None (iii) All 0x ! (d) (i) {all real x }, {all real y } (ii) All x (iii) None (e) (i) {all real x }, :y y 02" , (ii) All x (iii) None
13. (a) 2 2x ##- (b) (i) { x : 2 2x# #- }, { y: 0 2y# # } (ii) { x : 2 2x# #- }, { y: 2 0y# #- }
Exercises 5.10
1. (a) 21 (b) 10- (c) 8 (d) 3 (e) 3 (f) 75 (g) 0
(h) 6- (i) 41
(j) 1 (k) 7- (l) 3x x2 -
(m) 2 3 5x x3 + - (n) 3c2
2. (a) Continuous (b) Discontinuous at 1x = - (c) Continuous (d) Continuous (e) Discontinuous at x 2!=
Answer S1-S5.indd 785 8/2/09 2:48:01 AM
786 Maths In Focus Mathematics Extension 1 Preliminary Course
3. (a)
(b)
(c)
Exercises 5.11
1. (a) 0 (b) 0 (c) 0 (d) 2 (e) 1 (f) 6 (g) 32
(h) 0 (i) 5 x (j) 3
2. (a) x x
x
x x
11 3
3
RHS
LHS
2
2
2
= + +
=+ +
=
(b) 1 from above (c) 1 from below
3. (a) 2 from below (b) 2 from above
4. (a) 3x
(b) 4
5x2
5. (a)
(b)
(c)
(d)
(e)
Answer S1-S5.indd 786 7/12/09 1:34:32 AM
787ANSWERS
(f)
(g)
(h)
(i)
(j)
Exercises 5.12
1. 0x21
11- 2. 0 x31
1 1 3. x0 11 #
4. x21
01#- 5. 1 1x31
11 6. ,x x1 21$ - -
7. x2 252
1 # 8. ,x x6 31 2- -
9. ,x x32
12# 10. x232
21#- -
Exercises 5.13
1. (a) y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-4
-2
-11
(b) y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-4
-2
-11
(c) y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-4
-2
-11
Answer S1-S5.indd 787 7/11/09 1:26:51 AM
788 Maths In Focus Mathematics Extension 1 Preliminary Course
(d) y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-4
-2
-11
(e)
y = x +1
y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-4
-2
-11
(f)
y = 2x-3
y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-2
-11
(g)
x + y = 1
y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-2
-11
-4
(h)
3x - y - 6 = 0
y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-2
-11
-4
-5
-6
(i)
x + 2y - 2 = 0
y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
6
-3
-2
-11
-4
-5
-6
Answer S1-S5.indd 788 7/11/09 1:26:53 AM
789ANSWERS
(j)
x-4 -3 -2 -1 2 3 41
y
2
1
3
4
5
6
-3
-2
-1
-4
-5
-6
x =12
2. (a) x 32 - (b) y 2$ - (c) y x 1$ + (d) y x 422 -
(e) y 2x$
3. (a) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-2
-11
-4
-5
y = x2 - 1
(b)
-3 3
3
-3
y
x
(c) y
x-1 1
1
-1
(d)
x-3-4 -2 -1 2 3 4 51
y = x 2
y
1
2
3
4
5
-3
-2
-1
-4
-5
(e) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-8
-4
-21
y = x3
4. (a) y x3 21 - (b) y x 222 +
(c) x y 492 21+
(d) x y 812 22+
(e) ,x y5 21 2
Answer S1-S5.indd 789 7/11/09 1:26:55 AM
790 Maths In Focus Mathematics Extension 1 Preliminary Course
5. (a) y
x-4 -3 -2 -1 2 3 4
3
1
2
4
5
-2
-11
(b) y
x-4 -3 -2 -1 2 3 4
3
1
2
4
5
-2
-11
(c) y
x-4-5 -3 -2 -1 2 3 4
3
1
2
4
5
-2
-11
6. (a) y
x-4 -3 -1-2 2 3 4
3
1
2
4
5
6
-2
-3
-4
-11
(b) y
x-4 -3 -1-2 2 3 4
3
1
2
4
5
6
-2
-3
-4
-5
-6
-11
y = x - 3
(c) y
x-4 -3 -1-2 2 3 4
3
1
2
4
5
6
-2
-3
-4
-5
-11
y = 3x – 5
-6
(d) y
x-4 -3 -1-2 2 3 4
3
1
2
4
5
6
-2
-3
-4
-5
-6
-11
y = x + 1
y = 3 – x
Answer S1-S5.indd 790 8/2/09 4:42:53 AM
791ANSWERS
(e) y
x-3 3
3
-3
y = 1
(f) y
x-1-2 2
1
2
-2
x = – 1
(g) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-2
-11
-4
-5
y = x2
y = 4
(h) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-4
-21
-8
y = x3
y = 3
x = -2
(i) y
x-1 1
1
1
-1
(j) y
x-4 -3 -1-2 2 3 4
3
1
2
4
5
6
-2
-3
-4
-5
-6
-11
x - y = 2
x - y = -1
Answer S1-S5.indd 791 7/11/09 1:26:59 AM
792 Maths In Focus Mathematics Extension 1 Preliminary Course
7. (a) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-2
-11
-4
-5
y = x2
(b) y
x-4 -3 -2 -1 2 3 4
4
2
6
8
-6
-4
-21
-8
y = x3
y = 1
(c) y
x1-2 2
2
-2
x = 1
(d)
1-1 2 3 4
1
2
-2
y
x
y =2x
(e)
-1 2 3-2-3-4 1 4
1
2
-1
-2y =
1x + 2
x
y
8. (a)
x2 3 4 51-1-3-4 -2
y
y = x2
y = 5
x = 2
3
2
1
4
5
-2
-1
-3
-4
-5
Answer S1-S5.indd 792 7/11/09 1:27:01 AM
793ANSWERS
(b)
x2 3 41-1-3-4 -2
y
x=3
y=-1
y= x-2
3
2
1
4
5
6
-2
-1
-3
-4
-5
-6
(c)
x2 3 41-1-3-4 -2
y
y= 2x+ 1
2x- 3y= 6
3
2
1
4
5
6
-2
-1
-3
-4
-5
-6
(d)
-3 3
3
-3
x
x=-3
y= 2
y
(e)
x2 3 41-1-3-4 -2
y
y= 3
y= |x |
x= 2
3
2
1
4
5
6
-2
-1
-3
Test yourself 5
1. (a) f 2 6- =] g (b) f a a a3 42= - -] g (c) ,x 4 1= -
2. (a)
(b)
(c)
(d)
(e)
Answer S1-S5.indd 793Answer S1-S5.indd 793 8/11/09 11:31:52 AM8/11/09 11:31:52 AM
794 Maths In Focus Mathematics Extension 1 Preliminary Course
(f)
(g)
(h)
3. (a) Domain: all real x ; range: y 641
$ -
(b) Domain: all real x ; range: all real y (c) Domain: 1 1;x# #- range: 1 1y# #- (d) Domain: 1 1;x# #- range: 0 1y# # (e) Domain: 1 1;x# #- range: 1 0y ##- (f) Domain: all real ;x 0! range: all real y 0! (g) Domain: all real x ; range: all real y (h) Domain: all real x ; range: y 0$
4. 15 5. (a) 4 (b) 5 (c) 9 (d) 3 (e) 2
6.
7.
8.
9.
10.
11. (a) y 3# (b) y x 22 + (c) ,y x y 02$ #-
12. (a) Domain: all real ,x 3! range: all real y 0!
(b)
13. (a)
(b) (i) ,x 2 4= - (ii) 4 2x 11- (iii) ,x x2 42 1 -
Answer S1-S5.indd 794 7/11/09 1:27:04 AM
795ANSWERS
14. (a) 2 (b) 332
x = (c) 131
15. (a) x -intercept ,10- y -intercept 4 y(b) x-intercepts , ,2 7,- y-intercept y 14-
16. (a) i (b) iii (c) ii (d) i (e) iii
17. (a) 4 (b) 52
(c) 121
- (d) 3
18.
19. (a) Domain: 2,x $ range: 0y $
(b)
20. (a) ( ) 1( )
( )
f x( x x3f x(
xf x(
13 1x
4 2334 2
4 23x
= x4
=)= x4
=
] x-x g gxxx]34 34
So f x] g is even.
(b) ( )( ) ( )
( )( )
f x( x xf x( (
x x
f x(
3
3
3
3
= x=)= - +
= -
= -
] gx-x
So f x] g is odd.
2211.. (aaa)) y
x
1
(b)
x
y
-1 1
(c)
x
y
-4 4
2
(d) y
x
1
(e) y
x
-4 -3 -1
-2
-2 3 4 5
1
2
2114-
Answer S1-S5.indd 795 7/12/09 1:35:04 AM
796 Maths In Focus Mathematics Extension 1 Preliminary Course
Challenge exercise 5
1. ,b32
3= -
2.
3.
x2
y
-2
4.
5.
6. , ,f f f3 9 4 16 0 1= - = =] ] ]g g g
7. Domain: all real ;x 1!! range: ,y y1 02# -
8.
9. Domain: ;x 0$ range: y 0$ 10. , ,x 0 3 2= -
11.
12. h h h2 1 0 3 0 1 2+ - - = - + - - = -] ] ] ]g g g g
Answer S1-S5.indd 796 7/11/09 1:38:34 AM
797ANSWERS
13.
14.
15. ( ) ( )
( )
f a aa
f a
2 12 1
2 2
2
2
- = - -
= -
=
^ h
16. x4
1 41!=
17. (a) 2
2
x
xx
x
xx
xx
xx
x
31
32 3
31
32 6 1
32 7
32 7
31
RHS
LHS
`
= ++
=+
++
+
=+
+ +
=+
+
=
+
+= +
+
] g
(b) Domain: all real ;x 3! - range: all real y 2!
(c)
18.
19.
20. Domain: ;x 3$ range: 0y $ 21. Domain: x2 2# #-
22.
23. (a) 0 (b)
24.
Answer S1-S5.indd 797 7/11/09 1:38:38 AM
798 Maths In Focus Mathematics Extension 1 Preliminary Course
Chapter 6: Trigonometry
Exercises 6.1
1. , ,cos sin tan135
1312
512
i i i= = =
2. , ,sin cot sec54
43
35
b b b= = =
3. , ,sin tan cos74
757
74
5b b b= = =
4. , ,cos tan cosecx x x95
556
56
9= = =
5. ,cos sin53
54
i i= =
6. , ,tan sec sin25
23
35
i i i= = =
7. ,cos tan635
35
1i i= =
8. ,tan sin751
1051
i i= =
9. (a) 2 (b) 45c
(c) , ,sin cos tan452
145
2
145 1c c c= = =
10. (a) 3 (b) , ,sin cos tan3021
3023
303
1c c c= = =
(c) , ,sin cos tan6023
6021
60 3c c c= = =
11. .sin cos67 23 0 92c c= = 12. .sec cosec82 8 7 19c c= =
13. .tan cot48 42 1 11c c= = 14. (a) 2 61 2 29cos sinorc c
(b) 0 (c) 0 (d) 1 (e) 2
15. 80x c= 16. 22y c= 17. 31p c= 18. 25b c=
19. 20t c= 20. 15k c=
Exercises 6.2
1. (a) 47c (b) 82c (c) 19c (d) 77c (e) 52c
2. (a) 47 13c l (b) 81 46c l (c) 19 26c l
(d) 76 37c l (e) 52 30c l
3. (a) 77.75c (b) 65.5c (c) 24.85c
(d) 68.35c (e) 82.517c
4. (a) 59 32c l (b) 72 14c l (c) 85 53c l
(d) 46 54c l (e) 73 13c l
5. (a) 0.635 (b) 0.697 (c) 0.339 (d) 0.928 (e) 1.393
6. (a) 17 20c l (b) 34 20c l (c) 34 12c l
(d) 46 34c l (e) 79 10c l
Exercises 6.3
1. (a) 6.3x = (b) 5.6y = (c) 3.9b = (d) 5.6x = (e) 2.9m = (f) 13.5x = (g) 10.0y = (h) 3.3p = (i) 5.1x = (j) 28.3t = (k) 3.3x cm= (l) 2.9x cm= (m) 20.7x cm= (n) 20.5x mm= (o) 4.4y m= (p) 20.6k cm= (q) 17.3h m= (r) 1.2d m= (s) 17.4x cm= (t) 163.2b m=
2. 1.6 m 3. 20.3 cm 4. 13.9 m
5. (a) 18.4 cm (b) 13.8 cm 6. 10 cm and 10.5 cm
7. 47.4 mm 8. 20.3 m 9. (a) 7.4 cm (b) 6.6 cm (c) 9.0 cm
10. (a) 6.8 cm (b) 6.5 cm 11. 38 cm
Exercises 6.4
1. (a) x 39 48c= l (b) 35 06ca = l (c) 37 59ci = l (d) 50 37ca = l (e) 38 54ca = l (f) 50 42cb = l (g) x 44 50c= l (h) 3 10 5ci = l (i) 29 43ca = l (j) 45 37ci = l (k) 57 43ca = l (l) 43 22ci = l (m) 37 38ci = l (n) 64 37ci = l (o) 66 16cb = l (p) 29 56ca = l (q) 54 37ci = l (r) 35 58ca = l (s) °59 2i = l (t) 56 59cc = l
2. 37 57c l 3. 22 14c l 4. 36 52c l 5. 50c
6. (a) 11.4 cm (b) 37 52c l 7. ,31 58 45 44c ca b= =l l
8. (a) 13 m (b) 65 17c l 9. (a) 11 19c l (b) 26 cm
10. 4.96 cm and 17.3 cm 11. (a) 12.9 m (b) 56 34c l
Exercises 6.5
1. (a)
100c
Boat
Beachhouse
North
S6.indd 798 8/2/09 1:33:24 AM
799ANSWERS
(b)
320c
Campsite
Jamie
North
(c)
200c
Seagull
Jetty
North
(d)
50c
Alistair
Bus stop
North
(e)
B Hill285c
Plane
North
(f)
12c
Dam
FarmhouseNorth
(g)
160cHouse
Mohammed
North
(h)
80c
Town
Mine shaft
North
(i)
349cSchool
YvonneNorth
S6.indd 799 7/11/09 1:23:44 PM
800 Maths In Focus Mathematics Extension 1 Preliminary Course
(j)
Island
Boat ramp
280c
North
2. (a) 248c (b) 145c (c) 080c (d) 337c (e) 180c
3. 080c 4. 210c 5. 160c 6. 10.4 m
7. 21 m 8. 126.9 m 9. 72 48c l
10. (a) 1056.5 km (b) 2265.8 km (c) 245c
11. 83.1 m 12. 1.8 km 13. 12 m 14. 242c 15. 035c
16. 9.2 m 17. 171 m 18. 9.8 km 19. 51 41c l 20. 2.6 m
21. 9 21c l 22. 1931.9 km 23. 34.6 m 24. 149c
25. 198 m 26. 4.8 km 27. 9.2 m 28. 217c
29. (a) 1.2 km (b) 7.2 km 30. (a) 13.1 m (b) 50 26c l
Exercises 6.6
1. (a) 2
3 1+ (b) 1 (c) 2 (d) 4 (e)
34 3
(f) 3
2 3
(g) 141
(h) 4
6 24
2 3 1+=
+^ h (i) 3
(j) 2 3- +^ h (k) 0 (l) 1 (m) 2 2 1-^ h (n) 6
(o) 131
(p) 3 2 2- (q) 2 3 (r) 21
- (s) 632
(t) 2 3
2-
2. (a) 2
3 2x = (b)
29 3
y = (c) 2 3p =
3. 60c 4. 2 m 5. 3 m 6. 3
10 3m
7. (a) 6 2 m (b) 4 m 8. 0.9 m 9. 3
5 3 3m
+^ h
10. 100 3 m
Exercises 6.7
1. (a) 1 st , 4 th (b) 1 st , 3 rd (c) 1 st , 2 nd (d) 2 nd , 4 th (e) 3 rd , 4 th (f) 2 nd , 3 rd (g) 3 rd (h) 3 rd (i) 2 nd (j) 4 th
2. (a) 3 rd (b) 21
- 3. (a) 4 th (b) 2
1-
4. (a) 2 nd (b) 3- 5. (a) 2 nd (b) 2
1
6. (a) 1 st (b) 23
7. (a) 1 (b) 2
1 (c) 3- (d)
21
(e) 21
- (f) 21
- (g) 23
(h) 3
1- (i)
23
- (j) 2
1-
8. (a) 2
1- (b)
23
- (c) 3 (d) 23
- (e) 23
-
(f) 3- (g) 21
(h) 3
1- (i)
2
1 (j)
2
1-
9. (a) 23
- (b) 3 (c) 23
(d) 21
(e) 21
- (f) 3
(g) 2
1 (h)
2
1 (i) −1 (j)
21
10. ,sin cos53
54
i i= - = -
11. ,cos tan733
33
4i i= - = -
12. ,cos cosecx x89
8589
= = -
13. , ,cosec cot tanx x x21
5
21
2221
= - = - = -
14. ,cos sinx x74
7 7474
5 74= - = -
15. ,tan sec65
4
65
9i i= - =
16. , ,tan sec cosecx x x355
38
55
8= = - = -
17. (a) 103
sinx = (b) 1091
,91
3cos tanx x= - = -
18. , ,cot sec cosec65
561
661
a a a= - = = -
19. ,sin cot1051
51
7i i= = -
20. (a) sin i (b) cos x (c) tan b (d) sin a- (e) tan i-
(f) sin i- (g) cos a (h) tan x-
Exercises 6.8
1. (a) ,20 29 159 31c ci = l l (b) ,120 240c ci = (c) ,135 315c ci = (d) ,60 120c ci = (e) ,150 330c ci = (f) ,30 330c ci =
(g) , , ,30 120 210 300 0 2 720c c c c c c# #i i= ] g (h) 70 , 110 , 190 , 230 , 310 , 350
0 3 1080c c c c c c
c c# #
i
i
=
] g
S6.indd 800 7/12/09 1:45:15 AM
801ANSWERS
(i) , , ,30 150 210 330c c c ci = (j) , , , , , , , ,
, , ,15 45 75 105 135 165 195 225255 285 315 345c c c c c c c c
c c c c
i =
2. (a) 79 13! ci = l (b) ,30 150c ci = (c) ,45 135c ci = -
(d) ,60 120c ci = - - (e) ,150 30c ci = -
(f) ,30 150! !c ci =
(g) , , ,22 30 112 30 67 30 157 30c c c ci = - -l l l l
(h) , , , , ,15 45 75 105 135 165! ! ! ! ! !c c c c c ci =
(i) ,135 45c ci = - (j) , , ,30 60 120 150! ! ! !c c c ci =
3.
4. 1-
5.
6. , ,x 0 180 360c c c= 7. 1- 8. 1
9. ,x 0 360c c=
10.
11. 0 12. 270x c= 13. , ,x 0 180 360c c c=
14. , ,x 0 180 360c c c= 15. ,x 270 90c c= -
16.
17.
Exercises 6.9
1. (a) cos i (b) tan i- (c) cos i (d) tan i (e) sec a-
2. (a) sin i (b) sec i (c) cosec x (d) cos 2 x (e) sin a
(f) cosec 2 x (g) sec 2 x (h) tan2 i (i) cosec5 2 i
(j) sin 2 x (k) 1 (l) sin cosi i
3. (a) 1cos xLHS 2= -
sin
sinx
x1 1
RHS
2
2
= - -
= -
=
So cos sinx x12 2- = -
(b) sec tanLHS i i= +
cos cossin
cossin
1
1
RHS
i i
i
i
i
= +
=+
=
So sec tancos
sin1i i
i
i+ =
+
(c) 3 3 tanLHS 2 a= +
( )tansec
cos
sin
3 13
3
1
3
RHS
2
2
2
2
a
a
a
a
= +
=
=
=-
=
So tansin
3 31
32
2a
a+ =
-
S6.indd 801 7/11/09 1:24:10 PM
802 Maths In Focus Mathematics Extension 1 Preliminary Course
(d) sec tantan tan
cosec cot
x xx x
x x
11
LHS
RHS
2 2
2 2
2 2
= -
= + -
=
= -
=
So sec tan cosec cotx x x x2 2 2 2- = -
(e) sin cossin cos sin cossin cos sin sin cos cossin cos sin cos
sin sin cos cos sin cos
x xx x x xx x x x x xx x x xx x x x x x
21 2
2 2
LHS
RHS
2 2
2 2
= -
= - -
= - - +
= - -
= - - +
=
3
2
]] ]] ^] ]
gg gg hg g
So sin cos sin sin cos cossin cos
x x x x x xx x2
2
2
2
- = - -
+
3] g
(f) sin cossin sin
sin coscos sin
sin coscos
sin cossin
sincos
coscot sec
1 2
2
2
2
2
RHS
LHS
2
2
2
i i
i i
i i
i i
i i
i
i i
i
i
i
ii i
=- +
=+
= +
= +
= +
=
So cot secsin cossin sin
21 22
i ii i
i i+ =
- +
(g) cos cotsin cot
sinsincos
sin cos
90LHS
RHS
2
2
2#
c i i
i i
ii
i
i i
= -
=
=
=
=
] g
So 90cos cot sin cos2 c i i i i- =] g
(h) cosec cot cosec cotcosec cot
cot cot
x x x xx xx x1
1
LHS
RHS
2 2
2 2
= + -
= -
= + -
=
=
] ]g g
So cosec cot cosec cotx x x x 1+ - =] ]g g
(i)
( )
cos
sin cos
cos cos
sin cos
sec sintan costan costan cos
1
1
1 11 1
LHS
RHS
2
2 2
2 2
2 2
2 2
2 2
2 2
2 2
i
i i
i i
i i
i i
i i
i i
i i
=-
= -
= -
= + - -
= + - +
= +
=
So cos
sin costan cos
12
2 22 2
i
i ii i
-= +
(j) cosec
cotcos
cosec
cot cos cosec
cosec
cot cossin
cosec
cot cot
cosecsin
1
1
11
1
1
LHS
#
b
bb
b
b b b
b
b bb
b
b b
b
b
=+
-
=+ -
=
+ -
=+ -
=
=
tan cot
sec
cos
sin
sin
cos
sec
sin cos
sin cos
sec
sin cos
sec
seccos sin
cos
cos sin
sin
1
1
11
RHS
2 2
#
#
b b
b
b
b
b
b
b
b b
b b
b
b b
b
bb b
b
b b
b
=+
=
+
=+
=
=
=
=
LHS RHS=
So cosec
cotcos sin
1
b
bb b
+- =
4.
( )
cos sincos sincos sin
x y2 2
4 444 14
LHS
RHS
2 2
2 2
2 2
2 2
i i
i i
i i
= +
= +
= +
= +
=
=
=
] ]
]
g g
g
So 4x y2 2+ =
5.
( )
cos sincos sincos sin
x y9 9
81 818181 181
LHS
RHS
2 2
2 2
2 2
i i
i i
i i
= +
= +
= +
= +
=
=
=
2 2] ]
]
g g
g
So 81x y2 2+ =
S6.indd 802 7/11/09 1:24:20 PM
803ANSWERS
Exercises 6.10
1. (a) 8.9x = (b) 9.4y cm= (c) 10.0a =
(d) 10.7b m= (e) 8.0d =
2. (a) 54 57ci = l (b) c61 23a = l (c) x 43 03c= l
(d) 87 04ca = l (e) 150 56ci = l
3. 126 56c l 4. (a) 13.5 mm (b) 25 mm
5. (a) 1.8 m (b) 2.7 m 6. 5.7 cm
7. (a) 10.3 m (b) 9.4 m 8. (a) 60 22c l (b) 57 9c l
9. (a) 14.1 cm (b) 15.6 cm
10. (a) 54.7 mm (b) 35.1 mm
Exercises 6.11
1. (a) 5.8m = (b) 10.4b m= (c) 7.4h cm=
(d) 16.4n = (e) 9.3y =
2. (a) 51 50ci = l (b) 60 27ci = l (c) x 57 42c= l
(d) 131 31cb = l (e) 73 49ci = l
3. 32.94 mm 4. 11.2 cm and 12.9 cm
5. (a) 11.9 cm (b) 44 11c l (c) 82 13c l
6. ,XYZ XZY YXZ66 10 47 40c c+ + += = =l l
7. (a) 18.1 mm (b) 80 49c l 8. (a) 6.2 cm (b) 12.7 cm
9. 12.9 cm 10. (a) 11 cm (b) 30c
Exercises 6.12
1. 12.5 cm and 4.7 cm 2. (a) 040c (b) 305c 3. 16.4 m
4. 103c 5. 1.97 m 6. 11c
7. (a) 1.21 km (b) 1 minute 8. 32 m 9. 107 m
10. (a) .sin
sinAC
101 365 8 42 29
c
c=
l
l (b) 74 50ci = l
11. 8.5h = 12. 7.7 km 13. 5.7 km and 5.4 km
14. 1841 km 15. 35.8 m 16. 89 52c l 17. 9.9 km
18. 163.5 km 19. 64.1 m 20. 3269 km
21. (a) 11.3 cm (b) 4044c l 22. 141c
23. (a) 11.6 cm (b) 73 14c l
24. (a) 265.5 km (b) 346 33c l
25. (a) 35 5c l (b) (i) 4.5 m (ii) 0.55 m
Exercises 6.13
1. (a) 7.5 cm2 (b) 32.3 units2 (c) 9.9 mm2 (d) 30.2 units2 (e) 6.3 cm2
2. 2
15 3m2 3. 7.5 cm2 4. 15.5 cm2 5. 34.8 cm2
6. 1.2 m2 7. 42 cm2 8. 247.7 mm2
9. (a) 7.8 cm (b) 180.8 cm2
10. (a) 5.6 cm (b) 18.5 cm2 (c) 19.1 cm2
Exercises 6.14
1. (a) 2 m (b) 2.2 m (c) 65 21c l 2. (a) 1.9 m (b) 49 46c l
3. (a) 109 cm2 (b) 16 20c l 4. 965c l
5. (a) 9 m (b) 25 7c l 6. (a) 56 m (b) 89.7 m
7. (a) 48 m (b) 128.6 m (c) 97.7 m 8. 84 m
9. 16 50c l 10. 11 10c l
Exercises 6.15
1. (a) sin cos cos sina b a b- (b) cos cos sin sinp q p q-
(c) tan tan
tan tan
1 a b
a b
-
+ (d) sin cos cos sinx x20 20c c+
(e) tan tan
tan tanx
x1 48
48c-
+ (f) cos cos sin sin2 2i a i a+
(g) cos cos sin sinx x75 75c c- (h) tan tan
tan tan
x y
x y
1 5 7
5 7
+
-
(i) sin cos cos sin4 4a b a b- (j) tan tan
tan tan
1 3
3
a b
a b
+
-
2. (a) sin a b+] g (b) tan 65c (c) cos 55c (d) 2 3sin x y+^ h
(e) tan 2i (f) sin 32c (g) sin cosa b2 (h) cos sinx y2
(i) sin sinx y2 (j) cos cosm n2
3. (a) 2 2
1 34
2 6+=
+ (b)
2 2
1 34
2 6+=
+
(c) 3 1
1 32
2 3 43 2
-
+=
+= +
(d) 1 3
1 32
2 3 43 2
-
+=
- += - +
^^
hh
(e) 2 2
1 34
2 6-=
- (f)
2 2
3 14
6 2-=
-
(g) 2 2
1 34
2 6+=
+
S6.indd 803S6.indd 803 8/11/09 11:38:03 AM8/11/09 11:38:03 AM
804 Maths In Focus Mathematics Extension 1 Preliminary Course
(h) 1 3
1 32
4 2 32 3
-
+=
- += - +
^ ^h h
(i) sin cosx x2
3 12
1 3-+
+e eo o
(j) cos cosy y2
22=
4. tan x2 5. (a) 12
6 35+ (b)
123 5 2 7+
(c) 3 5 2 7
6 3517
32 5 27 7
-
+=
+
6. (a) sin cos2 i i (b) cos sin2 2i i- (c) tan
tan
1
22 i
i
-
7. (a) sin cos sin3 2 3i i i-
(b) cos sin cos33 2i i i- (c) tan
tan tan
1 3
32
3
i
i i
-
-
8. (a) tan 4i (b) sin cos cos sin7 3 7 3i i i i-
9. cos cos sin sinx x x x2 7 2 7- 10. (a) 2
1 (b) 3
(c) 23
- (d) 23
- (e) 3
1
11. (a) 54
(b) 1312
(c) 6533
- (d) 5
12 (e) 3
1615
-
12. (a) cos cosx y2 (b) [ 115 ]cos cos21
15c c+ -] g
13. (a) sin cosx y2 (b) sin sinx y2- (c) cos sinx y2
(d) cos cos sin sin sin cos cos sinx y x y x y x y- + -
(e) tan tan
tan tan
x y
x y
1
2 12 2
2
-
+_ i (f)
tan tan
tan tan
x y
y x
1
2 12 2
2
-
+^ h
14. (a) sin cosb b2 (b) tan
tan
1
22 i
i
- (c) cos sin2 2i i-
(d) sin cos cos sinsin cos sin cos sin cosx y x yx y y x y y
2 222 2
+
= - +_ i
(e) cos cos sin sin
cos sin cos sin cos sin
2 2
22 2
a b a b
a a b a a b
-
= - -^ h
(f) tan tan
tan tan
tan tan tan
tan tan tan tanx y
x y
y x y
x x y y1 2
2
1 2
22
2
-
+
=- -
- +
(g) sin cos cos sinsin cos cos cos sin sin sin2 2
2 2 2
i d i d
i i d i d i d
-
= - +
(h) cos cos sin sin
cos cos sin sin sin cos
2 2
22 2
i c i c
i c c i c c
+
= - +_ i
(i) tan tan
tan tan
tan tan tan
tan tan tan tanx z
x z
z x z
x x z z1 2
2
1 2
22
2
+
-=
- +
- -
(j) sin cos cos sinsin cos cos sin
sin cos cos sin
x y x yx x y y
y y x x
2 2 2 22
2
2 2
2 2
-
= -
- -
_^
ih
15. (a) sin x6 (b) cos y14 (c) tan 10i (d) cos y2
(e) sin21
12i (f) sin x1 2+ (g) cos 6a (h) cos 80c
(i) tan 2b (j) sin x1 6-
16. (a) 2 2
142
= (b) 21
(c) 3
1 (d)
21
(e) 3 (f) 23
(g) 2
1 (h) 1 (i)
2 2
1 (j)
21
-
17. ,cos sinx x2327
232
5 39= - =
18. (a) 6563
(b) 257
(c) 169120
(d) 5633
-
19. 4 sin cos cos sinsin cos sin cos4 4
2 2
3 3
i i i i
i i i i
- =
-
^ h
20. (a) tan x (b) 2 3
12 3
+= -
21. 2 1-
22. (a) 2
( )
sin tan
sin cos tan
sin coscossin
sin
sin sin tan
21
21
2
21
2
RHS
LHS
2
2`
i i
i i i
i ii
i
i
i i i
=
=
=
=
=
=
(b)
2
2
2
sincos
sin cos
cos sin
sin cos
cos sin
sin cos
sin sin
sin cos
sin
cos
sin
tan
tansin
cos
1
22 2
12 2
2 2
12 2
2 2
2 2
2 2
22
2
2
2
21
RHS
LHS
2 2
2 2
2 2
2
`
i
i
i i
i i
i i
i i
i i
i i
i i
i
i
i
i
i
i
i
=-
=
- -
=
- +
=
+
=
=
=
=
=-
d n
S6.indd 804 7/11/09 1:24:22 PM
805ANSWERS
23. 11 3( ) ( )
( )( )
( ) ( )
sin sinsin sinsin cos cos sinsin cos cos sin
sin cos cos sinsin sin sin sinsin sin sin sin sin sinsin sin
7 4 7 47 4 7 47 4 7 47 4 7 47 1 4 1 7 47 7 4 4 7 47 4
RHS
LHS
2 2 2 2
2 2 2 2
2 2 2 2 2 2
2 2
i ii i i ii i i ii i i i
i i i i
i i i i
i i i i i i
i i
=
= + -
= +
-
= -
= - - -
= - - +
= -
=
sin sin sin sin7 4 11 32 2` i i i i- =
24. ( )
( )
( )
coscoscos cos sin sincos sin cos sin cos
cos sin cos sin coscos sin coscos cos coscos cos cos
cos cos
32
2 22
233 13 3
4 3
LHS
RHS
2 2 2
3 2 2
3 2
3 2
3 3
3
ii ii i i i
i i i i i
i i i i i
i i i
i i i
i i i
i i
=
= +
= -
= - -
= - -
= -
= - -
= - +
= -
=
cos cos cos3 4 33` i i i= -
25. sin sinx x3 4 3-
Exercises 6.16
1. (a) tan i (b) cos i (c) tan 20c (d) cos 50c
(e) sin 2i (f) cos i
2. (a) 23
(b) 2
1 (c)
21
(d) 0
3. (a) tt
21 2+
(b) 1
1
t
t2
2
-
+ (c)
21
tt2-
(d) 1
2 1
t
t t2
2
+
+ -
(e) 1
1 2
t
t t2
2
-
- + (f)
1
1
t
t2
2
-
+ (g)
1
3 3 8
t
t t2
2
+
- + (h)
1t
(i) 11
tt
-
+ (j)
1
4 1
t
t t2 2
2
+
-
^^
hh
4. sin cossin cos
t
t
t
t
t
t
t
t
t
t t t
t
t t t
tt t
t
t t
t
11
11
2
1
1
11
2
1
1
1
1 2 1
1
1 2 1
2 22 2
2 1
2 1
LHS
RHS
2 2
2
2 2
2
2
2 2
2
2 2
2
i i
i i=
+ +
+ -
=
++
++
-
++
-+
-
=
+
+ + + -
+
+ + - +
=+
+
=+
+
=
=
]]
gg
sin cossin cos
t11
`i i
i i
+ +
+ -=
5. t
t t t t
1
4 4 1 62 2
3 2 4
+
- - + -
^ h
6. (a) sin5 26 34ci + l] g (b) sin2 60ci +] g (c) sin2 45ci +] g (d) sin29 21 48ci + l] g (e) sin17 14 2ci + l] g (f) sin10 18 26ci + l] g (g) sin13 56 19ci + l] g (h) sin65 60 15ci + l] g (i) sin41 38 40ci + l] g (j) sin34 59 2ci + l] g
7. (a) sin2 45ci -] g (b) sin5 63 26ci - l] g (c) sin2 60ci -] g (d) sin2 30ci -] g (e) sin29 21 48ci - l] g
8. cos10 18 26ci - l] g 9. cos2 60ci +] g 10. (a) sin85 12 32ci + l] g (b) cos85 77 28ci - l] g Exercises 6.17
1. (a) ,x 45 225c c= (b) ,x 30 210c c=
(c) , , , ,x 0 60 180 300 360c c c c c=
(d) , , , ,x 0 45 180 225 360c c c c c=
(e) , ,x 90 210 330c c c= (f) 0 , 60 , 300 , 360x c c c c=
( g) 0 , 45 , 180 , 225 , 360x c c c c c= (h) 0 , 180 , 360x c c c=
(i) 30 , 135 , 150 , 315x c c c c= (j) 0 , 360x c c=
2. (a) ,126 52 306 52c ci = l l (b) ,35 58 189 16c ci = l l
(c) 60 , 240c ci = (d) 180 , 270c ci =
(e) ,240 43 327 21c ci = l l (f) 90 , 180c ci =
(g) ,90 340 32c ci = l (h) ,56 34 176 34c ci = l l
(i) ,51 2 190 54c ci = l l (j) ,160 32 270c ci = l
3. (a) 180 30n 1 n# ci = + -] g (b) 180 60n ca = +
(c) n360 30! ci = (d) x n180 1 30n# c= - -] g
(e) 180 45n ci = - (f) n 45360 ! cb =
(g) n180 60! cc = (h) 180 30n ci = +
(i) n360 75 49! ci = l (j) n180 1 23 31n# ca = + - l] g
4. , , ,x 52 30 82 30 97 30 127 30c c c c= - -l l l l
5. ,x n n180 1 30 0 9036# !c c= + - n] g
6. , , ,x 180 0 90 180c c c c= -
7. (a) n180i = (b) 360x n= (c) 180x n=
(d) ( )n 1 270180 n ci = + - (e) n360 90! c
8. (a) (i) ,x 30 150c c= (ii) x n180 1 30n! c= + -] g
(b) (i) ,x 41 25 318 35c c= l l (ii) x n360 41 25! c= l
(c) (i) ’,x 71 34 251 34c c= l (ii) x n180 71 34c= + l
(d) (i) ,x 161 34 341 34c c= l l (ii) x n180 18 26c= - l
(e) (i) 45x c= (ii) 180 ( 1)x n 4590n c c= + - -
S6.indd 805 7/25/09 1:47:50 PM
806 Maths In Focus Mathematics Extension 1 Preliminary Course
9. 180 30 , 180 ( 1) 270x n n1 n# c c= + - + -n] g
10. (a) , , ,x 0 120 240 360c c c c= (b) , nn 360360 120! c
Test yourself 6
1. ,cos sin34
5
34
3i i= =
2. (a) cos x (b) 2 (c) cosec A (d) cos i (e) cos 20i
3. (a) 0.64 (b) 1.84 (c) 0.95
4. (a) 46 3ci = l (b) 73 23ci = l (c) 35 32ci = l
5.
( )
sincos
sinsin
sinsin sin
sinsin
12
12 1
12 1 1
2 12 2
LHS
RHS
2
2
i
i
i
i
i
i i
ii
=-
=-
-
=-
+ -
= +
= +
=
^
] ]
h
g g
2 2sin
cossin
12
So2
i
ii
-= +
6. b 40c= 7. (a) 2
1 (b)
23
- (c) 3-
(d) 21
- (e) 221140
-
8. ,x 120 240c c=
9.
,x 90 270c c=
10. 122 km 11. 5 3 12. (a) 6.3 cm (b) 8.7 m
13. (a) 65 5ci = l (b) 84 16ci = l (c) 39 47ci = l
14. 65.3 cm2 15. (a) ,x 60 120!! c c=
(b) , , ,x 15 105 75 165c c c c= - -
(c) , , ,x 0 180 30 150!c c c c= -
16. ,sin cot53
34
i i= - = 17. (a) 209c (b) 029c
18. n180 1 30 53 8n c ci = + - + l] g
19. (a) sin
sinAD
9920 39
c
c= (b) 8.5 m
20. 2951 km 21. (a) 2 2
3 14
2 3 1+=
+^ h
(b) 2 2
1 34
2 1 3-=
-^ h (c)
2 2
142
=
22. (a) x n360 60! c= (b) 180 45x n c= +
(c) 180 60x n 1 n# c= + -] g
23. , ,0 120 360c c ci = 24. 51 40ca = l
25. (a) cos x y+^ h (b) cos cos cos sin sincos sin
sin sinsin
x x x x x xx x
x xx
11 2
2 2
2 2
2
+ = -
= -
= - -
= -
]
^
g
h
Challenge exercise 6
1. 92 58c l 2. 50.2 km 3. 12.7x cm=
4. (a) .sin
sinAC
41 2125 3 39 53
c
c=
l
l (b) 25.2h cm= 5. 4.1 km
6. cos x- 7. 16 3 cm2 8. 2
1
9. , , ,x 22 30 112 30 202 30 292 30c c c c= l l l l 10. 75 45ci = l
11. 5.4 m 12. ,110 230c ci = 13. 6.43 km
14. 956
- 15. 31 m 16. sin
cos sin cos
coscos
sin cos
cossin cos
tan
1
1
LHS
RHS
2
2
i
i i i
ii
i i
i
i i
i
=-
+
=+
=+
= +
=
]
]
g
g
17. 4 5 0x y y2 2+ + - = 18. (a) 65 m (b) 27 42c l
19. (a) 52 37c l (b) 9 m 20. 30 8c l
21. 6 4 6 4( )
( )
cos cos sin sincoscoscos sincos cos
cos
6 4105 55 1 5
2 5 1
LHS
RHS
2 2
2 2
2
i i i ii ii
i i
i i
i
= -
= +
=
= -
= - -
= -
=
6 4 6 4 2 5 1cos cos sin sin cos2` i i i i i- = -
22. 30.1 , 0.5m ms 1- 23. °, °, °30 150 270i =
24. 180 ( 1) 270n n ci = + - 25. t-
S6.indd 806 7/11/09 1:24:26 PM
807ANSWERS
Chapter 7: Linear functions
Exercises 7.1
1. (a) 5 (b) 10 (c) 13 2. (a) 13 (b) 65
(c) 85 (d) 52 2 13=
3. (a) 9.85 (b) 6.71 (c) 16.55 4. 12 units
5. , 134 128Two sides side= =
6. Show 85AB BC= =
7. Show points are 17 units from ,7 3-^ h 8. 3 , 9x yRadius units equation 2 2= + =
9. Distance of all points from ,0 0^ h is 11, equation
11x y2 2+ = 10. 3a = 11. a 6 2!= -
12. All 3 sides are 2 units. 13. ,a 10 2= -
14. , ,MQ NP QP MN37 20= = = = so parallelogram
15. 98BD AC= = 16. (a) ,AB AC BC40 4= = =
(b) OC OB 2= = 17. 2 101 18. 61 units
19. 29, 116, 145AB BC AC= = =
AB BC
AC
29 116145
2 2
2
+ = +
=
=
So triangle ABC is right angled (Pythagoras’ theorem)
20. , ,XY YZ XZ65 130 65= = =
Since XY YZ= , triangle XYZ is isosceles.
XY XZ
YZ
65 65130
2 2
2
+ = +=
=
So triangle XYZ is right angled. (Pythagoras’ theorem)
Problem
30.2
Exercises 7.2
1. (a) ,2 4^ h (b) ,1 1-^ h (c) ,2 1-^ h (d) ,3 2-^ h (e) ,1 1-^ h (f) ,3 2-^ h (g) ,3
21d n (h) ,1
21
1d n (i) ,
21
221d n (j) ,0 5
21d n
2. (a) ,a b9 3= = - (b) ,a b5 6= - =
(c) ,a b1 2= - = - (d) ,a b1 2= - = -
(e) ,a b6 1= =
3. ,2
3 30
24 4
0+ -
=- +
=] g
4. ,P Q 2 1= = -^ h 5. ,4 3^ h 6. 3x = is the vertical line through
midpoint ,3 2^ h .
7. Midpoint of , .AC BD 221
321
midpoint of= = d n
Diagonals bisect each other
8. 125,AC BD= = midpoint AC midpoint=
,BD 421
= - ;d n rectangle 9. ,8 13-^ h
10. (a) , , ,X Y Z21
321
21
21
1 1= - = =, ,d d ^n n h
(b) , ; ,XY BC XZ10 40 2 10234
= = = =
; ,AC YZ AB3422
2= = =
11. 4x y2 2+ = 12. 1x y2 2+ =
Exercises 7.3
1. (a) 2 (b) 131
(c) 131
- (d) 252
- (e) 32
(f) 81
-
(g) 421
- (h) 32
- (i) 241
(j) 2- 2. 21y1 =
3. 1.8x = 4. 9x = 5. (a) Show 53
m m1 2= =
(b) Lines are parallel .
y
-3 -2 -1 3 4 5 6 7
1
3
4
-2
-1 2(2, -1)
(-2, 1)
(7, 2)
(3, 4)
1
2
6. Gradient of 1AB CD21
gradient of= =
Gradient of 0BC ADgradient of= =
7. Gradient of 1AB CD31
gradient of= = -
Gradient of BC AD43
gradient of= =
Gradient of ,AC 521
= -
gradient of 21
BD = -
8. Gradient of 1,AC = gradient of BD 1= -
9. (a) Show AB BC AC2 2 2+ =
(b) Gradient of 45
,AB =
gradient of 54
BC = -
Answer S7-S8.indd 807 7/12/09 3:00:43 AM
808 Maths In Focus Mathematics Extension 1 Preliminary Course
10. (a) , , ,F G1 2 421
= - =^ dh n (b) Gradient of FG BC
65
gradient of= =
11. 4 3 11 0x y- - = 12. Gradient of ,2 4-^ h and , ,3 1 3 1gradient of- = -^ ^h h and ,5 5 3=^ h
13. 1 14. 0.93 15. 21 16. 50 12c l 17. 108 26c l
18. (a) 3 (b) 3
1 (c) 3-
19.
tantan
m
m
7 45 2
33
1
1180 45 2135
nd quadrant` c c
c
ii
i
=-
- - -
=-
= -
=
- =
= -
=
]
^
g
h
20. 3
2 3 3x =
+^ h
Exercises 7.4
1. (a) (i) 3 (ii) 5 (b) (i) 2 (ii) 1 (c) (i) 6 (ii) 7-
(d) (i) 1- (ii) 0 (e) (i) 4- (ii) 3 (f) (i) 1 (ii) 2-
(g) (i) 2- (ii) 6 (h) (i) 1- (ii) 1 (i) (i) 9 (ii) 0
(j) (i) 5 (ii) 2- 2. (a) (i) 2- (ii) 3 (b) (i) 5- (ii) 6-
(c) (i) 6 (ii) 1- (d) (i) 1 (ii) 4 (e) (i) 2- (ii) 21
(f) (i) 3 (ii) 121
(g) (i) 31
- (ii) 2- (h) (i) 54
- (ii) 2
(i) (i) 321
(ii) 21
- (j) (i) 132
(ii) 32
3. (a) 4 (b) 2-
(c) 0 (d) 2- (e) 1- (f) 3- (g) 2 (h) 41
- (i) 121
(j) 141
(k) 32
(l) 21
(m) 51
(n) 72
(o) 53
-
(p) 141
- (q) 15 (r) 121
- (s) 61
(t) 83
-
Exercises 7.5
1. (a) 4 1y x= - (b) y x3 4= - + (c) 5y x=
(d) 4 20y x= + (e) 3 3 0x y+ - = (f) x y4 3 12 0- - =
(g) 1y x= - (h) 5y x= + 2. 8 0x y+ - =
3. (a) 4 3 7 0x y- + = (b) 3 4 4 0x y- + =
(c) 4 5 13 0x y- + = (d) 3 4 25 0x y+ - =
(e) 2 2 0x y- + = 4. 4 8 0x y+ - = 5. (a) 3y =
(b) x 1= - 6. y x2= - 7. 3 4 12 0x y- - =
8. 2 3 0x y+ - = 9. 4x = - 10. 3 8 15 0x y+ - =
Exercises 7.6
1. (a) 3- (b) 31
(c) 43
(d) 121
(e) 1 (f) 65
- (g) 3
1
(h) 31
(i) 3
1 (j)
51
2. (a) 1 0x y- + = (b) 3 16 0x y- + = (c) 5 0x y+ - =
(d) 2 5 0x y+ + = (e) 2 4 0x y- + =
(f) 3 1 0x y+ - = (g) 3 4 13 0x y+ + =
3. 3m m1 2= = so parallel
4. m m51
5 11 2 #= - = - so perpendicular
5. 151
m m1 2= =
6. m m37
73
11 2# #= - = - 7. 32
k = - 8. 4m m1 2= =
9. AB CD m m 31 2< = =_ i and BC AD m m85
1 2< = = -d n 10. Gradient of : ,AC m
21
1 = gradient of BD : 2,m2 = -
m m21
2 11 2# #= - = -
11. (a) y x= - (b) 5 8 0x y- - = (c) 2 2 0x y+ + =
(d) 2 3 16 0x y- + = 12. 7 6 24 0x y+ - =
13. 3 0x y+ - = 14. 2 5 0x y- - =
15. 2 3 18 0x y- + =
Exercises 7.7
1. (a) ,2 4-^ h (b) ,1 3- -^ h (c) ,4 4^ h (d) ,0 2-^ h (e) ,5 1-^ h (f) ,1 1-^ h (g) ,3 7^ h (h) ,4 0^ h (i) ,41 26^ h (j) ,
191
197
-d n 2. Substitute ,3 4-^ h into both lines
3. , , ,2 5 4 1^ ^h h and ,1 1- -^ h 4. All lines intersect
at ,2 3-^ h 5. All lines meet at ,5 0-^ h 6. 11 6 0x y+ =
7. 5 6 27 0x y+ - = 8. x y4 7 23 0+ =+
9. 1 0x y+ - = 10. 2 2 0x y+ - =
11. 3 0x y+ - = 12. 2 3 0x y- - =
13. x y 1 0- + = 14. 3 2 0x y- + =
15. 3 7 0x y+ - = 16. 5 13 0x y+ + =
17. 27 5 76 0x y- - = 18. 3 14 0x y- - =
19. 2 1 0x y- - = 20. 3 11 0x y- - =
21. 5 17 0x y- + =
Answer S7-S8.indd 808 8/2/09 1:50:05 AM
809ANSWERS
Exercises 7.8
1. (a) 2.6 (b) 1133
(c) 2.5 (d) 2.4 (e) 138
2. (a) 3.48 (b) 1.30 (c) 0.384 (d) 5.09 (e) 1.66
3. (a) 13
7 13 (b) 5 (c)
2054 205
(d) 13
5 26 (e)
1314 13
4. d d d 11 2 3= = =
5. : , :A d B d5
14
5
3= =
-
Opposite signs so points lie on opposite sides of the line
6. , : , , :d d2 310
139 2
10
5- = =^ ^h h
Same signs so points lie on the same side of the line
7. , : , , :d d3 2 4 4 1 251
- = - =^ ^h h
Opposite signs so points lie on opposite sides of the line
8. 2d d1 2= = so the point is equidistant from both lines
9. , : , , :d d8 337
551 1
37
9- = =^ ^h h
Same signs so points lie on same side of the line
10. , : , , :d d3 25
64 1
5
7- =
-=^ ^h h
Opposite signs so points lie on opposite sides of the line
11. 4d d1 2= = so same distance 12. 5
8 5 units
13. 1 14. 4.2 15. 9 17x32
or= - 16. 3 1b41
121
or= -
17. m 1 1832
31
or= - -
18. Show distance between ,0 0^ h and the line is 5
19. Show distance between ,0 0^ h and the line is greater than 1
20. (a) , , , , ,3 1 374
71
2 2- -^ d ^h n h (b) , ,5
2 105
13 5119
26 34
Exercises 7.9
1. (a) 18 26c l (b) 29 45c l (c) 82 52c l (d) 26 34c l
(e) 10 29c l (f) 41 49c l (g) 72 15c l (h) 18 26c l
(i) 74 56c l (j) 36 52c l
2. (a) 149 2c l (b) 119 45c l (c) 143 58c l (d) 172 14c l
(e) 135c 3. 12 20c l 4. 53 58c l
5. , ,21 2 120 58 38c c cl l 6. ,m 331
= -
7. . , .m 5 4 1 53= - 8. . , .k 1 64 0 095Z -
9. (a) ,A C B D63 26 116 34c c+ + + += = = =l l
(b) 124 31c l 10. ,A B C61 56 59 2c c+ + += = =l l
Exercises 7.10
1. (a) ,53
152
-d n (b) ,251
353d n (c) ,2
94
198
-d n
(d) ,471
172
-d n (e) ,2109
221
-d n (f) ,5 241
-d n
(g) ,276
776d n (h) ,3
114
1111
- -d n (i) ,76
174
-d n
(j) ,132
132
-d n
2. (a) ,4 321
-d n (b) ,654
2d n (c) ,19 25^ h (d) ,12 521d n
(e) ,40 12^ h (f) ,9 174
-d n (g) ,621
- -d n (h) ,9 132d n
(i) ,58 30-^ h (j) ,10 13^ h
3. (a) ,E32
2= d n (b) ,F 132
2= d n (c) ,EF AC AC EF1 3 3`= = =
4. A B(3, 2) (-1, 6)(1 , 3 )2
313 ( , 4 )1
323
5. , , ,P Q PQ153
51
16 19 24 units= = - =,d ^n h
6. ,B 954
1252
= -d n 7. ,p q453
20= =
8. (a) ,32
132d n (b) Each ratio gives , .
32
132d n This means
that the intersection of the medians divides each median in the ratio : .2 1
9. ,a b8 18= = 10. 92
, 398
P = d n
Test yourself 7
1. 6.4 units 2. ,221
2-d n
3. (a) 151
- (b) 2 (c) 3
1 (d)
53
4. (a) 7 11 0x y- - = (b) 5 6 0x y+ - = (c) 3 2 0x y+ =
(d) 3 5 14 0x y+ - = (e) 3 3 0x y- - =
5. 5
6 5units
6. ,m m41
41 2= - = so m m 11 2 = -
` lines are perpendicular.
7. x -intercept 5, y -intercept 2-
8. (a) 2 1 0x y+ - = (b) 21
(c) 25
units
9. 5,m m1 2= = so lines are parallel 10. 3 4 0x y- =
Answer S7-S8.indd 809 8/2/09 1:50:06 AM
810 Maths In Focus Mathematics Extension 1 Preliminary Course
11. ,1 1-^ h 12. ,a b6 1= = 13. 66 48c l
14. Solving simultaneously, 4 0x y- - = and
2 1 0x y+ + = have point of intersection , .1 3-^ h
Substitute ,1 3-^ h in 5 3 14 0:x y- - =
5 1 3 3 14 0LHS RHS# #= - - - = =
point lies on 5 3 14 0:x y- - =
Substitute ,1 3-^ h in 3 2 9 0:x y- - =
3 1 2 3 9 0LHS RHS# #= - - - = =
point lies on 3 2 9 0:x y- - =
lines are concurrent
15. ,295
131
-d n 16. 0.499- 17. ,c 13 65= - -
18. 3y = 19. ,4 7^ h 20. 154
x = 21. 93 22c l
22. , : , , :d d2 113
86 3
13
2- =
-=^ ^h h
Opposite signs so points lie on opposite sides of the line
23. 63 26c l 24. 4 0x y- - = 25. 3 7 14 0x y- - =
Challenge exercise 7
1. 2k = - 2. 3 3 3 0x y- - = 3. 10 10 81x y2 2+ =
4. Show AC and BD have the same midpoint ,1 2^ h and m m 1AC BD# = -
5. Show distance of all points from ,0 0^ h is 3; radius 3; equation 9x y2 2+ =
6. 13
4 13 7. 45 ; ( )OBA a b sides of isoscelesc+ D= =
8. 13
12 13 9. 113 12c l 10. 2 3 13 0x y+ + =
11. .angled
, , ;,
BC AC ABm m
18 61
so is isoscelesso is rightBC AC#
D
D
= = =
= -
12. ,3 5-^ h
13. ,a b2 3= = 14. 2 5 14 0x y+ + = 15. 45c
16. 3 3 2 3 0x y+ + - = 17. 6 0x y- + =
18. ,b 231
21= - 19. , , ,231
231
132
332
- -d dn n 20.
m m
m m
m m
m m
m m m m
m m m m
m m
m m
m m m m
m m m m
11
11
11
11
11
or
1 2
1 2
1 2
1 2
1 2 1 2
1 2 1 2
1 2
1 2
1 2 1 2
1 2 2 1
`
+
-=
+
-=
+ = -
= - -
+
-= -
- = - -
= - -
21. ,Pp
p
p
p
1
4 1
1
7 3=
-
- -
-
-f p
22. (a) AB : 7 5 14 0x y+ + =
,7 7-^ h lies on the line (show by substitution)
(b) :1 2- or :1 2-
23. ,x y1632
17= = - 24. . , .m 0 059 9 2= - -
25. (a) ,P 132
331
= d n (b) ,Q 431
331
= d n (c) PQ has gradient 0m1 =
AC has gradient 0m2 =
Since ,m m PQ AC1 2 <=
(d) ,R 631
0= d n
(e) PR has gradient 75
m1 = -
BC has gradient 75
m2 = -
Since ,m m PR BC1 2 <=
Chapter 8: Introduction to calculus
Exercises 8.1
1.
2.
3.
Answer S7-S8.indd 810 7/25/09 2:05:37 PM
811ANSWERS
4.
5.
6.
7.
8.
9.
10.
Exercises 8.2
1. Yes, 0x = 2. Yes, x x1= 3. No 4. Yes, 0x =
5. Yes, ,x x x x1 2= = 6. Yes, 0x = 7. Yes, x 3= -
8. Yes, 2x = 9. Yes, ,x 2 3= - 10. Yes, x1 01#-
11. Yes, ,x 90 270c c= 12. Yes, 0x = 13. No 14. No
15. Yes, x 3!=
Exercises 8.3
1. (a) 3 (b) 7- (c) 3 (d) 8 (e) 2 (f) 3- (g) 2 (h) 1- (i) 10 (j) 1-
2. (a) 2 4x x2 - - (b) 2 1x x3 + - (c) 7 1x- - (d) 4x x4 2- (e) 4 3x- + (f) 2 6x2 + (g) 2x- (h) 4x2 (i) 3 1x - (j) 2 9x x2 - +
Exercises 8.4
1. (a) 4.06 (b) 3.994 (c) 4
2. (a) 13.61 (b) 13.0601 (c) 12.9401 (d) 13 3. 6
4. (a) 2f x h x xh h2 2+ = + +] g
(b) ( ) ( )f x h f x x xh h xxh h
22
2 2 2
2
+ - = + + -
= +
(c) h
f x h f x
hxh h
hh x h
x h
2
2
2
2+ -=
+
=+
= +
] ]
]
g g
g
(d) ( )
( )
lim
lim
f xh
f x h f x
x h
x
2
2
h
h
0
0
=+ -
= +
=
"
"
l] ]g g
5. (a) ( ) ( )( )
f x h x h x hx xh h x hx xh h x h
2 7 32 2 7 7 32 4 2 7 7 3
2
2 2
2 2
+ = + - + +
= + + - - +
= + + - - +
] g
(b) ( ) ( ) ( )( )
f x h f x x xh h x hx x
x xh h x hx x
xh h h
2 4 2 7 7 32 7 3
2 4 2 7 7 32 7 3
4 2 7
2 2
2
2 2
2
2
+ - = + + - - +
- - +
= + + - - +
- + -= + -
Answer S7-S8.indd 811 7/11/09 1:21:39 PM
812 Maths In Focus Mathematics Extension 1 Preliminary Course
(c)
h
f x h f x
hxh h h
hh x h
x h
4 2 7
4 2 7
4 2 7
2+ -=
+ -
=+ -
= + -
] ]
]
g g
g
(d) f x x4 7= -l] g
6. (a) f 2 11=] g (b) 2 5 11f h h h2+ = + +] g
(c) f h f h h2 2 52+ - = +] ]g g
(d)
h
f h f
hh h
hh h
h
2 2 5
5
5
2+ -=
+
=+
= +
] ]
]
g g
g
(e) f 2 5=l] g
7. (a) f 1 7- = -] g
(b) f h f h h h1 1 4 12 123 2- + - - = - +] ]g g (c) 12
8. (a) f 3 8=] g (b) f h f h h3 3 6 2+ - = +] ]g g (c) f 3 6=l] g
9. (a) f 1 13= -l] g (b) 17
10. (a) 2y x x2= +
Substitute ,x x y yd d+ +_ i :
( )
2
y y x x x xx x x x x x
y x xy x x x x
22 2 2
2 2Since
2
2 2
2
2
d d d
d d d
d d d d
+ = + + +
= + + + += +
= + +
] g
(b) x
y
xx x x x
x
x x x
x x
2 2
2 2
2 2
2
d
d
d
d d d
d
d d
d
=+ +
=+ +
= + +
] g
(c) 2 2dx
dyx= +
11. (a) 2 (b) 5 (c) 12- (d) 15 (e) 9-
12. (a) f x x2=l] g (b) 2 5dx
dyx= +
(c) f x x8 4= -l] g (d) 10 1dx
dyx= -
(e) 3dx
dyx2= (f) f x x6 52= +l] g
(g) 3 4 3dx
dyx x2= - + (h) x xf 6 2= -l] g
13. (a) 0.252 (b) 0.25 (c) 0.2498
14. (a) 0.04008- (b) 0.03992- (c) 0.04- 15. 1-
Exercises 8.5
1. (a) 1 (b) 5 (c) 2 3x + (d) 10 1x - (e) 3 4 7x x2 + - (f) 6 14 7x x2 - + (g) 12 4 5x x3 - + (h) 6 25 8x x x5 4 3- - (i) 10 12 2 2x x x4 2- + - (j) 40 63x x9 8-
2. (a) 4 1x + (b) 8 12x - (c) 2 x (d) 16 24x x3 - (e) 6 6 3x x2 + -
3. (a) x3
1- (b) x x2 3 2- (c) 3
86
xx
75- (d) 4 x (e)
41
(f) 2 2 2x x2 - +
4. f x x16 7= -l] g 5. 56-
6. 60 40 35 3dx
dyx x x9 7 4= - + - 7. 10 20
dtds
t= -
8. g x x20 5= - -l] g 9. 30dtdv
t= 10. 40 4dtdh
t= -
11. drd
rV
4 2r= 12. 3 13. (a) 5 (b) 5- (c) 4x =
14. (a) 12 (b) x 2!= 15. 18
Exercises 8.6
1. (a) 72 (b) 13- (c) 11 (d) 18- (e) 18 (f) 27
(g) 11 (h) 136 (i) 4- (j) 149
2. (a) 261
- (b) 251
(c) 201
(d) 431
- (e) 101
(f) 71
(g) 711
- (h) 201
(i) 81
- (j) 51
-
3. (a) (i) 6 (ii) 61
- (b) (i) 8 (ii) 81
-
(c) (i) 24 (ii) 241
- (d) (i) 8- (ii) 81
(e) (i) 11 (ii) 111
-
4. (a) 27 47 0x y- - = (b) 7 1 0x y- - = (c) 4 17 0x y+ + = (d) 36 47 0x y- - = (e) 44 82 0t v- - =
5. (a) x y24 555 0+ - = (b) 8 58 0x y- + = (c) 17 516 0x y- - = (d) 45 3153 0x y- + = (e) 2 9 0x y+ - =
6. (a) (i) 7 4 0x y- + = (ii) 7 78 0x y+ - = (b) (i) 10 36 0x y- + = (ii) 10 57 0x y+ - = (c) (i) 10 6 0x y+ - = (ii) 10 41 0x y- - = (d) (i) 2 2 0x y+ + = (ii) 2 19 0x y- - = (e) (i) 2 2 0x y- + = (ii) 2 9 0x y+ - =
7. x 3!= 8. (1, 2) and ( 1- , 0) 9. ( 5- , 7- )
10. (0, 1) 11. (1, 2) 12. ,143
41615
- -d n 13. (a) (1, 1- ) (b) 6 7 0x y- - =
14. 10 7 0t h- - = 15. x y4 2 19 0- - =
Answer S7-S8.indd 812 8/2/09 1:50:06 AM
813ANSWERS
Exercises 8.7
1. (a) 3x 4- - (b) 1.4x0.4 (c) 1.2x 0.8- (d) 2x21 -
1
(e) 2x x3 2+-
-
1
(f) 3x-
2
(g) 4x6-
1
(h) 2x-
3
2. (a) x
12
- (b) 2
5
x (c)
6
1
x56 (d)
10
x6- (e)
15
x4
(f) 2
1
x3- (g)
3
x7- (h)
23 x
(i) 3
2
x2-
(j) 2
1 12
x x3 5- -
3. 271
4. −3 5. 321
6. −3 7. 2 3 1x x+ +
8. 81
9. 3 16 8 0x y+ - = 10. 9 0x y- + =
11. (a) 2
1
x3- (b)
161
- 12. x y16 016+ - = 13. (9, 3)
14. 4x = 15. , , ,552
552
- -d dn n
Exercises 8.8
1. (a) 4 3x 3+] g (b) 6 2 1x 2-] g (c) 70 5 4x x2 6-^ h
(d) 48 8 3x 5+] g (e) 5 1 x 4- -] g (f) 135 5 9x 8+] g (g) x4 4-] g (h) 4 6 3 2 3x x x2 3 3
+ +^ ^h h (i) 8 2 5 5 1x x x2 7
+ + -] ^g h (j) 6 6 4 2 3x x x x5 6 2 5
- - +^ ^h h (k) 2x23
3 1--
1] g
(l) 2 4 x 3- -] g (m) 6 9x x2 4- -
-^ h (n) -
3x35
5 4+2] g
(o) -
4x x x x x43
3 14 1 72 3 2- + - +
1^ ^h h (p) 2 3 4
3
x +
(q) 5 2
5
x 2-
-] g (r) 1
8
x
x2 5
-+^ h (s)
7 3
2
x3-
-
(t) 2 4
5
x 3-
+] g (u) 4 3 1
3
x 3-
-] g (v) 2 2 7
27
x 10-
+] g
(w) 3 3
4 9 3
x x x
x x4 3 2
3 2
-- +
- +
^^
hh (x)
316 4 1x3 +
(y) 4 7
5
x 94 -] g
2. 9 3. 40 4. (4, 1) 5. ,x 2 121
= - 6. 8 7 0x y+ + =
Exercises 8.9
1. (a) 8 9x x3 2+ (b) 12 1x - (c) 30 21x +
(d) 72 16x x5 3- (e) 30 4x x4 -
(f) 5 2 1x x x 2+ +] ]g g (g) 8 9 1 3 2x x 4- -] ]g g (h) x x x3 16 7 43 2- -] ]g g (i) 10 13 2 5x x 3+ +] ]g g (j) x x x x x x x
x x x x x
10 5 3 1 3 10 1
13 60 3 20 1
3 2 2 4 2 2 5
3 2 2 4
+ - + + + +
= + + - +
^ ^ ^ ^^ ^
h h h hh h
(k) x
xx
x
x
2 22
2 2
4 3-
-+ - =
-
-
(l) x
xx x2 1
2 5 32 1
5
2 1
112 2-
- ++
-= -
-]]
]gg
g
2. 26 3. 1264 4. 77
1
7
8+ = 5. 176
6. 10 9 0x y- - = 7. 69 129 0x y- - =
8. x3
6 30!=
- 9. 34 29 0x y- + =
Exercises 8.10
1. (a) x2 1
22-
-
] g (b) 5
15
x 2+] g (c) x
x x
x
x x
4
12
4
122 2
4 2
2 2
2 2
-
-=
-
-
^ ^^
h hh
(d) 5 1
16
x 2+] g (e) 14 14
x
x x
x
x4
2
3
- +=
- + (f)
3
11
x 2+] g
(g) 2
2
x x
x2 2
2
-
-
^ h (h) 2
6
x 2-
-
] g (i) x4 3
342-
-
] g (j) x3 1
142+
-
] g
(k) 3 7
3 6 7
x
x x2 2
2
-
- - -
^ h (l) x
x x
x
xx
2 3
4 12
2 3
342
2
2-
-=
-
-
] ]]
g gg
(m) x
x
5
182 2-
-
^ h (n) x
x x
x
x x
4
2 12
4
2 62
3 2
2
2
+
+=
+
+
] ]]
g gg
(o) x
x x
3
2 9 72
3 2
+
+ +
] g (p) 3 4
3 8 5
x
x x2
2
+
+ -
] g
(q) x x
x x x
1
2 4 12 2
4 3 2
- -
- - -
^ h (r)
-2 2
xx x x
52 5 5
+
+ - +
1 1
] ]g g
(s)
(t) 28
x
x x x
x
x
7 2
7 1 7
7 2
21 302 28 5
4 3
+
-=
+
- ++ - +
]] ] ]
]gg g g
g
(u) x
x x x x
x
x x2 5
15 2 5 3 4 6 3 4 2 5
2 5
3 3 4 4 33
6
3 4 5 2
4
4
-
- + - + -
=-
+ -
]] ] ] ]
]] ]
gg g g g
gg g
(v) x
x x
x
x
x1
1 2 1
3 1
2 1
3 53+
+ +
+
=+
+-3
] g
(w) x
x
x
x
x x
x
2 3
2 1
2 3
1
2 1 2 3
2 12 2-
-
-
-=
- -
- +2-
] ]g g
(x) x
x
x x
x x
x x
x x
9
1
9
9 1
1 9
9 24
2
2
2
2 3
2
-
+
-
- +=
+ -
- - -2-
]
]]
]g
gg
g
x
x x x
x
x x
5 1
6 5 1 2 9 5 2 9
5 1
2 9 20 512
2 3
2
2
+
+ - - -=
+
- +
]] ] ]
]] ]
gg g g
gg g
Answer S7-S8.indd 813 8/2/09 1:50:07 AM
814 Maths In Focus Mathematics Extension 1 Preliminary Course
2. 81
3. 195
- 4. 0, 1x = 5. 9, 3x = -
6. 18 8 0x y- + = 7. 17 25 19 0x y- - =
Exercises 8.11
1. (a)
(b) Substitute Q into both equations .
(c) 4y x2= - has 4m1 =
8 12y x x2= - + has 4m2 = -
(d) 28 4c l
2. (a)
(b) ,P 3 9= ^ h (c) 6m = (d) 0c 3. 8 8c l
4. 71 34c l 5. 162 54c l 6. (a) , , ,X Y4 16 1 6= = -^ ^h h (b) : ,
: ,X m mY m m
12 78 3
AtAt
1 2
1 2
= =
= - = -
(c) : :X Y3 22 11 19At Atc cl l
7. ,71 34 8 58c cl l 8. (a) (0, 0), (2, 8), ( 1- , 1- )
(b) 63 26c l at (0, 0), 4 42c l at (2, 8), 71 34c l at ( 1- , 1- )
9. At (0, 0), 0 4m mand1 2= = At (2, 4), 4 0m mand1 2= = Angle at both is 75 58c l
10. 164 45c l at (0, 0), 178 37c l at ( 3- , 33- ), 146 19c l at (1, 3)
Test yourself 8
1. (a)
(b)
2. 10 3dx
dyx= - 3. (a) 42 9 2 8
dx
dyx x x5 2= - + -
(b) 2 1
11dx
dy
x 2=
+] g (c) 8( ) ( )dx
dyx x x9 2 4 4 22= + + -
(d) 40 5 5 (10 1)dx
dyx x x x x2 1 2 1 2 13 4 3= - + - = - -] ] ]g g g
(e) 2
5dx
dy x3
= (f) 10
dx
dy
x3= -
4. dtdv
t4 3= - 5. (a) 1 (b) 20 6. 10 7. 42
8. (a) 2x = - (b) 1x = (c) 2x =
9. (a) 32 4 9f x x 3= +l] ]g g (b) 3
5dx
dy
x 2= -
-] g
(c) dx
dyx x9 1 3 1= - -] ]g g (d)
4dx
dy
x2= -
(e) f xx5
145
=l] g
10. y
11. 9 7 0x y- - = 12. (2, 3) 13. drdS
r8r=
14. ( 2- , 71), (5, 272- ) 15. 4 6 0x y- - = 16. 3525
17. 9 18. x y12 4 0+ - = 19. ,51
dtds
u at t= + =
20. 107
21. 17 6c l at (3, 9), 853c l at ( 1- , 1)
22. 175 26c l at (2, 4), 177 40c l at (4, 16)
Answer S7-S8.indd 814 7/11/09 1:21:45 PM
815ANSWERS
Challenge exercise 8
1. ,f f1 3 1 36= - = -l] ]g g 2. 1813
-
3. ; , .dtdx
t t t8 300 0 37 53 2= + = -
4. , ,x y x y x y2 0 3 3 0 6 12 0+ = - - = - + =
5. , , , , 12 26 0, 12 170 0x y x y2 2 2 14- - + - = + + =^ ^h h 6.
43
7. 5 5 1 9 15 9 5 110 5 1 9 (4 13)x x x x
x x x
3 4 5 2
2 4+ - + - +
= + - -
] ] ] ]] ]g g g gg g
8. x
x x x
x
x4 9
2 4 9 16 2 1 4 9
4 9
2 12 17
8
4 3
5
-
- - + -
=-
- +
]] ] ]
]]
gg g g
gg
9. x12
6 2046
3 51! !=
-=
- 10. 2 25 0x y+ - =
11. 271
a = - 12. ,P 241
6161
= -d n 13. ,x31
31 13!
=
14. 21
15. , , ,x y Q PQ3 5 0 0 5 10- + = = =^ h
16. (a) Substitute (1, 1) into both curves:
3 2 :y x 5= -] g
13 1 2
11
LHSRHS
LHS
5
5
#
=
= -
=
=
=
] g
So (1, 1) lies on the curve 3 2y x 5= -] g
15 3
yxx
=+
- :
1
1 15 1 3
22
1
LHS
RHS
LHS
#
=
=+
-
=
=
=
So (1, 1) lies on the curve 1
5 3y
xx
=+
-
(1, 1) is a point of intersection
(b) 22 45c l
17. 8n = 18. , , x y11211
23 3
12 3 012 31- + =e o
19. , ,x21
121
153
= - 20. (a) ,x 90 270c c=
(b) y
x1
90c 180c 270c 360c
21. ,4 73- -^ h 22. 3 9 14 0x y- - = 23. x x
x
4 3 2
4 534 -
-] g
24. (a) ,x y x y16 32 1 0 4 2 1 0+ + = - - =
(b) 2m m21
1
1 2$ #= -
= -
So perpendicular
25. 0, 2, 6x = 26. ,a b14 7= - = 27. 22
5 22
28. 121
p = 29. drdV
38 3r
= 30. 4k = 31. 4 0x y- - =
32. 4 13 0x y- - = 33. 481
- 34. , ,a b c1 2 4= - = =
35. 8 8 2S r rhr r r= - +
36. (a) 6 5 3 1 3 5x x x2 3- - -] ]g g (b) x x
x
3 2 1
5 64- +
+-
]]g
g
37. x6
4 13!=
38. (a) 7 80 0x y+ - =
(b) ,Q 471
12491
= -d n
Practice assessment task set 2
1. 0.77- 2. 1 3. 5 2 1 0x y+ - = 4. ,2 2-^ h 5. 0.309- 6. (a) 3 cm2 (b) , 1AC BD13 cm cm= =
7. 1; ,m m A43
68
1 121
1 2 #= - = - = -d n 8. x 15c=
9. 127
Answer S7-S8.indd 815 8/2/09 3:28:23 AM
816 Maths In Focus Mathematics Extension 1 Preliminary Course
10.
11.
12. ’45 49c 13. Domain: all real ;x21
! range: all
real y 0!
14.
15.
16. sin4 i 17. 2 units 18. 8 15 0x y- + =
19. ,120 240c ci = 20. 132
- 21. 2 22. 11 565ca = l
23. .y 16 5= 24. 3 5 0x y+ - = 25. x132
31 1
26. 7 27. 3x = 28. 3-
29. Show perpendicular distance from ,0 0^ h to the line is 2 units, or solving simultaneous equations gives only one solution.
30. (a) ,g g2 1 3 6= - = -] ]g g
(b)
31. 3 4x x2 - 32. 2
1- 33. 17.5 m
34. ,x y2 17= - = - 35. (a) 7.0AB m= (b) 27.8 m 2
36. cos3 i 37. (a) 2 4 0x y- + = (b) , ,,P Q2 0 0 4-^ ^h h (c) 4 units 2
38. 127 m 39. 15 units 2 40. ( )
( )
f x x xx xf x
33
6 2
6 2
- = - - - -
= - -=
] ]g g
41. 16x x x x x1 1 18 1 2 12 22 2 2 2 2 33 4+ + + ++ =^ ^ ^ ^h h h h
42. y431
9# #- 43. 3
x2-
44. (a) 3 4 0x y- - = (b) 2 0x y- - =
(c) 3 10 0x y+ + = (d) ,R 10 0= -^ h 45.
138
units 46. Domain: all ;x 4!- range: all y 0!
47. 2 7
1
x - 48. 4.9 km 49. 8 7 10x x 3- - -
50. 1
5
x 2+] g 51. 2 3x - 52. x x
x
x x
x
5
17 2
5
17 22 2+
- -=
+
+- ] g
53. 6 56 0x y+ - = 54. ,f f2 45 2 48- = - - =l] ]g g
55. ,a b2 9= = - 56. 7 5 9 0x y- + =
57. 47 109 0x y- + = 58. 0.25x = - 59. ,33 17-^ h
60. 2 2
3 14
6 2+=
+ 61. 67 37c l
62. ,x 63 26 243 26c c= l l
Answer S7-S8.indd 816 7/11/09 1:22:03 PM
817ANSWERS
63.
64. (a) cos i (b) cos i b+^ h (c) tan 14a 65. 3
66. , .x x4 4 61 2 67. 12 32c l at both points
68. (a) domain: x21
$ range: y 0$
(b) domain: all real x 7!- range: all real y 0!
(c) domain: x2 2# #- range: y2 0# #-
69. ,a b15 1= - = - 70. cos 2i
71. (a) (0, 0), (1, 3), ( 1- , 1- ), (2, 20)
(b) 6 263c l at (0, 0), 2 20c l at (1, 3), 40 36c l at ( 1- , 1- ), 20 2c l at (2, 20)
72. (a) x n360 45! c= (b) x n180 30c= +
(c) x n180 1 60n# c= + -] g
73. (a) (1, 1) (b) 2 13 units (c) 121
-
(d) 3 2 5 0x y+ - =
74. (a) 75. (b), (d) 76. (a) 77. (c) 78. (c)
79. (b), (d) 80. (c)
Chapter 9: Properties of the circle
The proofs given as answers to this chapter are informal. Also, they may not be the only way to answer the question.
Exercises 9.1
1. (a) 32ci = (b) 8x cm= (c) 68 30ci a= = l (d) 31ci =
(e) 9x mm= (f) 3022ci = l
2. 9
16cm
r 3. (a) 29ci = (b) 18x c=
(c) ,83 42c ca b= = (d) 68x c= (e) 10x cm=
(f) 97y c= (g) , ,x y z15 150 75c c c= = =
(h) , ,x y z47 43 94c c c= = = (i) 40cb =
(j) 39x y c= =
4. (a) , ,x y z112 56 34c c c= = = (b) 49x c=
(c) ,x y55 43c c= = (d) ,x y166 7c c= =
(e) ,x 62 31c cb= =
(f) , , ,x y z v w32 58 32 17c c c c= = = = = (g) 5x c=
(h) 102y c= (i) 57 30 , 32 30x yc c= =l l
(j) , ,x y z75 77 13c c c= = =
5. (a) (vertically opposite )( s in the same segment)(similarly)
DCE ACBEDC BACDEC ABC
s+ + ++ + ++ +
=
=
=
Since all pairs of s+ are equal,
DECD;<ABCD
(b) 5.5x cm=
6.
° (angle at centre is double the at the circumference)( ° °) ( sum of isosceles )
xy
30180 30 2
75'
c
++ D
=
= -
=
7. ° ° ( at the centre is double theat the circumference)
°° (similarly)
x
xy
360 2 110
14070
#
`
++
- =
==
8. ( in semicircle)( sum of )
( in same segment)
ABCBAC
x
9090 296161
`
`
cc ccc
+ ++ +
+
D
=
= -
=
=
9. ( in same segment)(similarly)(vertically opposite )
STV WUVTSV UWVTVS UVW s
+ + ++ ++ + +
=
=
=
Since all pairs of angles are equal,
| WUVD||
.STV
x 2 4 cmD
=
10. ( )BAC AB BC
AC
AC
90
6 336 945
453 5
21
23 5
in semicircle
Radius
cm
2 2 2
2 2
c+ +=
= +
= +
= +
=
=
=
=
=
11. (Base s of isosceles )(similarly)
( at the centre is double theat the circumference)
OACBAOCAB
x CAB
302530 25552
2 55110
`
#
ccc cc
cc
+ +++
+++
D=
=
= +
=
=
=
=
Answer S7-S8.indd 817 7/25/09 2:05:40 PM
818 Maths In Focus Mathematics Extension 1 Preliminary Course
12. (a) ,x y2 765 c c= =
(b) AC BD= (equal diameters) Diagonals are equal so ABCD is a rectangle. AD BC` = (opposite sides of a rectangle)
13. 33ECB c+ = (angles in same segment)
EBC 180 114 33+ = - +] g (angle sum of triangle)
°33= ECB ADE`+ += These are equal alternate angles. AD BC` <
14. (a) 90AOB c+ = (given)
ABC 90c+ = (angle in semi-circle)
AOB ABC+ += A+ is common | ABCD||AOB`D ( AAA )
(Note 2 pairs of angles equal means 3 pairs will be equal by angle sum of triangle.)
(b) AO BO= (equal radii)
AB r r
r
r
r
2
22
2 2
2
2#
= +
=
=
=
By similar triangles
ABAO
BCBO
=
But soAO BO AB BC= =
So BC r2=
15. Obtuse 2BOD+ i= (angle at centre double
angle at circumference)
Refl ex 360 2BOD+ i= - (angle of revolution)
21
BCD BOD+ += (angle at centre double angle at circumference)
(360 2 )
18021
i
i
= -
= -
So BCD+ and DAB+ are supplementary (add to180c)
Exercises 9.2
1. (a) 5x cm= (b) 15y cm= (c) 2.4x m= (d) 42x c= (e) 90z c= (f) 10.3x mZ (g) 6 , 3x ym m= = (h) .m 13 4 cmZ (i) 5y cmZ (j) 5x mm=
2. 41 cm 3. 144 mm 4. 25.6 cm
5. . ..
..
(perpendicular from bisects chord)O
CE
CD
AB
11 5 6 99 22 9 218 4
2 2
#
= -
=
=
=
=
6. 8.3OB cm= 7. . , .x y4 7 1 8m m= =
8. 4.4 , 78 , 38 , 64x m c c cZ a b i= = =
9. OA r=
2
ACx
= (perpendicular from the
centre bisects a chord)
2
OC rx2
2
= - d n (Pythagoras’ theorem)
r
x
r x
r x
r x
4
44
4
44
24
22
2 2
2 2
2 2
= -
= -
=-
=-
CD r
r x
r r x
24
22 4
2 2
2 2
= +-
=+ -
10. (a) ECD ACB+ += (vertically opposite angles)
A E+ += (angles in same segment)
CDED|||ABC`D ( AAA )
(b) By similar triangles
CEAC
CDBC
=
. .AC CD BC CE=
Exercises 9.3
1. (a) ,x y107 94c c= = (b) ,134 90c ci c= = (c) , ,x y z112 112 68c c c= = = (d) ,x y92 114c c= = (e) , ,73 107 107c c cb a c= = = (f) ,x y141 63c c= = (g) ,x y65 43c c= = (h) , , ,w x y z89 86 54 35c c c c= = = = (i) , , ,w x y z69 111 82 98c c c c= = = = (j) 118x c=
2. (a) ,x y62 31c c= = (b) ,x y75 105c c= = (c) ,x y88 65c c= = (d) , ,x y z62 82 36c c c= = = (e) ,x y90 113c c= = (f) ,x y38 71c c= = (g) ,x y85 95c c= = (h) ,x y48 78c c= = (i) ,x y107 73c c= = (j) , , , ,a b c d e81 55 83 16 28c c c c c= = = = =
3. (a) 180 58A c c+ = - ( A+ and B+ cointerior angles,
AD BC; )
180 58D c c+ = - ( C+ and D+ cointerior angles, AD BC; )
So A C180c+ += - and D B180c+ += -
Since opposite angles are supplementary, ABCD is a cyclic quadrilateral.
(b) 90B D c+ += = (given)
180B D` c+ += -
Let A x+ =
360 90 90C x+ = - + +] g (angle sum of quadrilateral)
Answer S9-S10.indd 818 7/12/09 4:40:20 AM
819ANSWERS
xx
A
360 180180180 +
= - -
= -
= -
Since opposite angles are supplementary, ABCD is a cyclic quadrilateral.
(c) CDA 180+ i= - (straight angle)
B CDA180` c+ += -
Let A x+ =
360 90 90C x+ = - + +] g (angle sum of quadrilateral)
xx
A
360 180180180 +
= - -
= -
= -
Since opposite angles are supplementary, ABCD is a cyclic quadrilateral .
Exercises 9.4
1. (a) 47ci = (b) 5x m= (c) 11.3y cm= (d) 26x y c= = (e) ,a b64 32c c= = (f) 57ci = (g) 12p 145 cmZ= (h) 10y mm= (i) 5.79x cmZ (j) ,x y33 33c c= =
2. (a) 10x cm= (b) ,x y64 26c c= = (c) 13x cm= (d) ,x y27 54c c= = (e) 5y cm= (f) ,x y32 7c c= = (g) ,x y72 42c c= = (h) ,x y35 90c c= = (i) , , ,m n p q23 67 67 23c c c c= = = = (j) ,x y71 62c c= =
3.
( )
(tangent o radius)( sum of )
( radii)
(base s of isosceles )
( m of )
(opposite s of cyclic quad.)
( at centre twice at circumference)
OABz
OA OCOAC OCA y
y
ACD AED
y uuu
BAC OAB OACx
v AOC
AOB
OAC
9090 4842
180 48 2
66180
180 6266 118
52
90 6624
21
21
48
24
t
equal
su
`
`
'
`
`
#
cc cc
c c
cc
c cc c
c
c cc
c
c
=+
+ +
+ +
+ + +
+
+
+
+
+
+ +
D
D
D
=
= -
=
=
= =
= -
=
= -
+ = -
+ =
=
= -
= -
=
=
=
=
4. 21 cm
5. . ..
..
( ’ )
AC BC
AB
AB AC BCACB
3 9 5 242 256 542 25
90 by Pythagoras theorem
2 2 2 2
2 2
2 2 2`
` c+
+ = +
=
=
=
= +
=
A lies on a diameter of the circle (tangent ⊥ radius)
6. (a) x 67c= (b) 7.5y cmZ (c) ,x y72 121c c= = (d) ,x y63 126c c= = (e) 8.9 , 5.1x ym mZ= (f) ,x y63 63c c= = (g) , ,x y z98 65 17c c c= = = (h) ,x y57 57c c= = (i) ,x y72 15c c= = (j) , ,x y z61 70 52c c c= = =
7. (a) , ,x y z26 74 48c c c= = = (b) 68 , 44 , 68x y zc c c= = = (c) 45x y z c= = = (d) ,x y70 31c c= = (e) , ,x y z20 57 103c c c= = = (f) 5.4x cmZ (g) .x 7 7 cmZ (h) ,x y77 13c c= = (i) 1.2 , 2.1x ycm cmZ Z (j) , ,x y z55 112 57c c c= = =
8. 13AB mZ
Test yourself 9
1. 56ci = 2. 2.3y mm= 3. 7.2x m=
4. 12x y cm= =
5. c
cc ccc
( )( )
( )
( )
zy
x
19180 131 193030
s in same segmentsum of
s in same segment
+
+
+
D
=
= - +
=
=
6. 10x cm=
7. , ,3 44 136c c ca b c= = =
8.
90
(
a
OCAb
OC OEOCE
21
100
50
90 837
is isosceles
at centre twice at circumference)
(tangent perpendicular to radius)
(equal radii)
#
`
`
c
ccc cc
+
+ +
D
=
=
=
= -
=
=
( )OCE OEC c
ccc
2 100 1802 80
40
sum of`
c ccc
+ ++ D
= =
+ =
=
=
360 100
( )
(
(
COE
d260360 260 50 7
43
Reflex of revolution)
sum of quadrilateral)
c ccc c c c
c
+ +
+
= -
=
= - + +
=
9. 17 cm 10. 5.3 m 11. ,a b101 98c c= =
12. ,61 29c ca b= = 13. 14.9 cm 14. 4.9x m=
15. 18 cm 16. 127 , 53c ca b= =
17. ( )
47
( )
( )
D
y
180 80 5347
sum of
s in same segment`
c c ccc
+ + T
+
= - +
=
=
x 47c= ( s+ in alternate segment)
18. , ,x y z55 56 54c c c= = =
Answer S9-S10.indd 819 7/12/09 4:40:57 AM
820 Maths In Focus Mathematics Extension 1 Preliminary Course
19. C+ is common
A CBD+ += ( s+ in alternate segment)
| ABCD||BCD AAA` D ] g 20. (a)
( )OCB OCA
OA OB90 (given)
equal radiic+ += =
=
OC is common OAC OBC RHS` /D D ] g (b) AC BC= (corresponding sides in )s/ D
∴ OC bisects AB
Challenge exercise 9
1. 6 cm
2. Then
(base s of isosceles )( )( radii)
( of s of isosceles )
DOB DCB xEDO x
EO DOOED EDO x
ODC
EOD
2
2
Letext. ofequal
base`
+ ++
+ +
+
+
+
D
D
D
= =
=
=
= =
180 ( )
( )
( )
( sum of )
( straight )
EOD OED EDOx
AOE EOD DOB
x xx
AOE DCB
EOD
AOC
180 4180
180 180 433`
ccc
c c
+ + +
+ + +
+ +
+
+ +
D= - +
= -
= - +
= - - +
=
=
3. andThen
180 ( )180 ( )180
( in alternate segment)(similarly)
( sum of )( sum of )
( is straight )
DAB x CAB yDAC x yACB DAB xADB CAB yDBA x yCBA x y
DBA CBA
ADBACB
DBC
Let
s
ccc
+ +++ ++ +++
+ +
+
+
+
+
D
D
= =
= +
= =
= =
= - +
= - +
+ =
( ) ( )x y x y180 180 180` c c c- + + - + =
( )x yx y
DAC
180 290
90
`
`
`
cc
c+
= +
= +
=
4. (a) AD DB BE EC CF FA (equal radii)= = = = =
AB BC CA` = = ABC is equilateral`D
(b) r unitsr
(c) r r r321
22 3
units2 2 2 2rr
- =-e o
5. ( )BDE ABD BADABDABD
BAD2
ext. of`
+ + +++
+
a aa
D= +
= +
=
BAD AD BDis isosceles with` D =
( )CDE ACD CADACDACD
CAD
2ext. of
`
+ + +++
+
b b
b
D= +
= +
=
CAD AD CDAD BD CD
is isosceles with`
`
D =
= =
So a circle can be drawn through A , B and C with centre D .
6. Let ODC x+ = and .OAB y+ = Then you can fi nd all these angles (giving reasons).
AOC COB BOD AOD 360c+ + + ++ + + = ( + of revolution)
y x COB y x
AOD90 90
360c c
c+
+- + + + + - +
=
180 360
180COB AOD
COB AOD`
c c
c
+ ++ ++ + =
+ =
7. B
A
D
C
Let ABCD be a kite with AB AD= and ,BC DC= and °.ADC ABC 90+ += = AC is common.
∴ by SSS (or RHS) ABC ADC/D D
BAC DAC BCA DCAand+ + + += =
(corresponding s1 in congruent sD )
Then
90 ( sum of )
BAC DACBADBCA DCABCD
2
180 2
Let
`
c
c
+ +++ ++
+
aa
aa
D
= =
=
= = -
= -
Opposite angles are supplementary.
∴ ABCD is a cyclic quadrilateral, and A , B , C and D are concyclic points
Since ,ABC 90c+ = AC is a diameter. ( + in semicircle)
8. r
2825
units2
2r
Answer S9-S10.indd 820 7/12/09 4:41:15 AM
821ANSWERS
9. Let interval AB subtend angles of x at ADB+ and .ACB+
Assume A , B , C and D are not concyclic. Draw a circle through A , B and C that cuts AD at E .
Then AEB BCA x+ += = ( s+ in same segment)
But AEB+ and EDB+ are equal corresponding angles.
| DB|EB` (this is impossible!)
∴ A , B , C , D must be concyclic
10. Let ABCD be a quadrilateral with opposite angles supplementary. i.e. A C 180c+ ++ = and B D 180c+ ++ =
Assume the points are not concyclic. Draw a circle through A , B and C , cutting CD at E .
Now ABCE is a cyclic quadrilateral, so
180AEC B c+ ++ = (opposite s+ supplementary)
Also, 180D B c+ ++ = (given)
D AEC+ +=
These are equal corresponding angles, so DA EA< (this is impossible!)
∴ A , B , C and D must be concyclic
∴ ABCD is a cyclic quadrilateral.
Chapter 10: The quadratic function
Exercises 10.1
1. Axis of symmetry 1,x = - minimum value 1-
2. Axis of symmetry 1.5,x = - minimum value 7.5-
3. Axis of symmetry 1.5,x = - minimum value 0.25-
4. Axis of symmetry 0,x = minimum value 4-
5. Axis of symmetry 83
,x = minimum point ,83
167d n
6. Axis of symmetry 1,x = maximum value 6-
7. Axis of symmetry 1,x = - maximum point ,1 7-^ h 8. Minimum value ,1- 2 solutions
9. Minimum value 3.75, no solutions
10. Minimum value 0, 1 solution
11. (a) ;x 3= - (-3, -12) (b) ;x 4= - (-4, 17)
(c) ; ,x 141
141
381
= d n (d) ; ,x 141
141
1341
= - - -d n (e) ; ,x 3 3 23= - - -^ h
12. (a) (i) x 1= - (ii) -3 (iii) (-1, -3)
(b) (i) 1x = (ii) 1 (iii) (1, 1)
Answer S9-S10.indd 821 7/12/09 4:41:43 AM
822 Maths In Focus Mathematics Extension 1 Preliminary Course
13. (a) Minimum (-1, 0) (b) Minimum (4, -23) (c) Minimum (-2, -7) (d) Minimum (1, -1) (e) Minimum (2, -11)
(f) Minimum ,41
381
- -d n (g) Maximum (-1, 6)
(h) Maximum (2, 11)
(i) Maximum , 721
43d n
(j) Maximum (1, -3)
14. (a) (i) -2 (ii) Minimum 0 (iii) y
x-4 -3 -2 -1 2
3
2
1
4
5
-2
-3
-11
(b) (i) -1, 3 (ii) Minimum -4
(iii) y
x-4 -3 -2 -1 2 3 4
2
1
3
4
5
-3
-2
-11
-4
-5
(c) (i) 5.83, 0.17 (ii) Minimum -8
(iii) y
x-4 -3 -2 -1 2 3 4 5 6
4
2
6
8
10
-6
-4
-21
-8
-10
(d) (i) -2, 0 (ii) Minimum -1
(iii) y
x-4 -3 -2 -1 2
2
1
3
4
5
-3
-2
-11
(e) (i) 3! (ii) Minimum -18
(iii) y
x-2-3-4 -1 1 2 5
1
2
-6
-8
-10
-12
-14
-16
-18
-4
-243
(f) (i) -1, 32
(ii) Minimum 21
12-
Answer S9-S10.indd 822 7/12/09 5:04:29 AM
823ANSWERS
(iii) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-4
-5
-6
-2
-1
-2
1
112
23
(g) (i) 1.65, -3.65 (ii) Maximum 7
(iii) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
7
6
-3
-2
-11
(h) (i) 1.3, -2.3 (ii) Maximum 341
(iii) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-2
-11
3 14
(i) (i) 0.56, -3.56 (ii) Minimum 441
(iii) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
-3
-2
-11
4 14
(j) (i) 2.87, -0.87 (ii) Maximum 7
(iii) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
6
7
-3
-2
-11
15. (a) 4 (b) None
(c) y
x-4 -3 -2 -1 2 3 4 5
2
1
3
4
5
6
7
-3
-2
-11
Answer S9-S10.indd 823 8/2/09 2:58:15 AM
824 Maths In Focus Mathematics Extension 1 Preliminary Course
16. (a) None (b) 643
(c) y
x-4 -3 -2 -1 2 3 4 5
4
2
6
8
10
12
14
-3
-2
-11
17. (a) 387
- (b) None
(c)
18. (a) y
x-4 -3 -2 -1 2 3 4 5
4
2
6
8
-3
-2
-11
(b) ,x x2 31 2 (c) x2 3# #
19. y
x-4 -3 -2 -1 2 3 4 5
4
2
6
8
-6
-4
-21
Graph is always above the x -axis so y 02 for all x x x3 2 4 02` 2- + for all x
20. y
x-4 -3 -2 -1 2 3 4 5
4
2
6
8
-6
-4
-21
Graph is always above the x -axis so y 02 for all x x x 2 02` 2+ + for all x
21. y
x-4 -3 -2 -1 2 3 4 5
2
4
-18
-10
-12
-14
-16
-8
-6
-4
-21
Graph is always below the x -axis so y 01 for all x x x2 7 02` 1- + - for all x
y
x-4 -3 -2 -1 2 3 4 5
1
2
-18
-16
-14
1
-12
-10
-8
-6
-4
-2
Answer S9-S10.indd 824 7/12/09 5:10:54 AM
825ANSWERS
22.
Graph is always below the x -axis so y 01 for all x x x5 4 1 02` 1- + - for all x
Exercises 10.2
1. ,x x3 31 2- 2. 1 0n ##- 3. 0, 2a a# $
4. ,x x2 21 2- 5. y0 6# # 6. 0 2t 11
7. 4, 2x x1 2- 8. 3, 1p p# $- - 9. ,m m2 41 2
10. 3, 2x x# $- 11. h121
21 1 12. 4 5x ##-
13. 2 7k21# #- 14. ,q q 631 2 15. All real x
16. ,n n4 3# $- 17. x3 51 1- 18. t6 2# #-
19. ,y y31
51 2- 20. ,x x2 4# $- 21. x21
01 1-
22. x031
1 1 23. x0 11 # 24. 0x21
1#-
25. x1 131
1 1 26. ,x x1 21$ - - 27. 2 2x52
1 #
28. ,x x6 31 2- - 29. ,x x32
12#
30. x222
21#- -
Exercises 10.3
1. (a) 20 (b) -47 (c) -12 (d) 49 (e) 9 (f) -16 (g) 0 (h) 64 (i) 17 (j) 0
2. (a) 17 unequal real irrational roots (b) -39 no real roots (c) 1 unequal real rational roots (d) 0 equal real rational roots (e) 33 unequal real irrational roots (f) -16 no real roots (g) 49 unequal real rational roots (h) -116 no real roots (i) 1 unequal real rational roots (j) 48 unequal real irrational roots
3. 1p = 4. k 2!= 5. b87
# - 6. p 22 7. k 2121
2 -
8. a 3 02=
b ac4 1 4 3 7
830
2 2
1
- = - -
= -
] ] ]g g g
So x x3 7 02 2- + for all x
9. ,k k5 3$# - 10. k0 41 1 11. ,m m3 31 2-
12. ,k k1 1# $- 13. 3
p1
1 - 14. b0 221
# #
15. ,p p2 6# $-
16. Solving simultaneously: 2 6y x= + (1)
3y x2= + (2)
Substitute (2) in (1):
x xx xb ac
3 2 62 3 04 2 4 1 3
160
2
2
2 2
2
+ = +
- - =
- = - - -
=
] ] ]g g g
So there are 2 points of intersection
17. 3 4 0x y+ - = (1) 5 3y x x2= + + (2) From (1): 3 4y x= - + (3) Substitute (2) in (3):
5 3 3 48 1 0
4 8 4680
x x xx x
b ac 1 1
2
2
2 2
2
+ + = - +
+ - =
- = - -
=
] ]g g
So there are 2 points of intersection
18. 4y x= - - (1) y x2= (2) Substitute (2) in (1):
44 0
4 1 415
0
x xx x
b ac 1 4
2
2
2 2
1
= - -
+ + =
- = -
= -
] ]g g
So there are no points of intersection
19. 5 2y x= - (1) 3 1y x x2= + - (2) Substitute (2) in (1):
x x xx x
b ac
3 1 5 22 1 0
4 2 4 1 10
2
2
2 2
+ - = -
- + =
- = - -
=
] ] ]g g g
So there is 1 point of intersection the line is a tangent to the parabola
20. 341
p =
21. (c) and (d)
y
x-4 -3 -2 -1 2 3 4 5
1
2
-5
-6
-7
-4
-3
-2
-11
Answer S9-S10.indd 825 8/2/09 2:58:20 AM
826 Maths In Focus Mathematics Extension 1 Preliminary Course
Exercises 10.4
1. (a) , ,a b c1 2 6= = = - (b) , ,a b c2 11 15= = - = (c) , ,a b c1 1 2= = = - (d) , ,a b c1 7 18= = = (e) , ,a b c3 11 16= = - = - (f) , ,a b c4 17 11= = = (g) , ,a b c2 12 9= = - = - (h) , ,a b c3 8 2= = - = (i) , ,a b c1 10 24= - = = - (j) , ,a b c2 0 1= - = = -
2. , ,m p q2 5 2= = - =
3. 4 5 2 2 1 3 4x x x x x2 - + = - - + + +] ]g g
4. a x x b x cx x x
x x x xx x
2 3 21 2 3 1 2 17
3 2 6 2 172 9
RHS
RHS
2
2
= - + + - +
= - + + - +
= + - - + - +
= + +
=
] ] ]] ] ]
g g gg g g
true
5. , ,A B C1 5 6= = = - 6. , ,a b c2 1 1= = = -
7. , , .K L M1 6 7 5= = = 8. 12 5 2 3 65 2x x 2+ + - - -] ]g g
9. , ,a b c0 4 21= = - = -
10. (a) 5y x x2= - - (b) 3y x x2= -
(c) 2 3 7y x x2= - + (d) 4 9y x x2= + -
(e) 2 1y x x2= - - +
Exercises 10.5
1. (a) ,2 1a b ab+ = - = (b) . ,1 5 3a b ab+ = = - (c) . , .0 2 1 8a b ab+ = = - (d) ,7 1a b ab+ = - =
(e) ,232
1a b ab+ = =
2. (a) 3 (b) 6- (c) 0.5- (d) 21
3. (a) 3 10 0x x2 + - = (b) 4 21 0x x2 - - = (c) 5 4 0x x2 + + = (d) x x 08 112 - + = (e) 2 27 0x x2 - - =
4. 0.5m = 5. 32k = - 6. 4b = 7. 1k = 8. 13p =
9. 5k = - 10. m 3!= 11. 1k = - 12. ,n 1 3= -
13. ,p r2 7= = - 14. ,b c6 8= - = 15. ,a b0 1= = -
16. 11
`ab ba
= =
17. (a) 1k = - (b) 1, 0k = - (c) 1.8k = - (d) 3k =
(e) ,k k1 0# $-
18. (a) p 2 3!= (b) ,p p2 3 2 3# $-
(c) p2
3 3!=
19. (a) k 2= (b) 3k = - (c) 2k =
20. (a) 1m = (b) ,m m2
3 102
3 101 2
- +
(c) 3m = -
Exercises 10.6
1. (a) ,x 1 4= - - (b) 2, 5y = (c) 4, 2x = - (d) 1, 4n = - (e) 3, 5a = - (f) 3, 4p = (g) ,x 2 4= - (h) 5, 12k = (i) ,t 6 4= - (j) ,b 12 4= - -
2. (a) 2, 3x = - (b) 2, 3x = (c) 4, 5x = (d) 3, 5x =
(e) 121
x = , 4
3. (a) x 3!= (b) ,y 2 2! != (c) x2
1 5!=
(d) . , . , . , .x 1 37 4 37 0 79 3 79= - - (e) ,a 2 2 6!= - -
4. (a) 0, 3x = (b) 1p = (c) 1x = (d) 1x = (e) 1, 3x =
5. 2,x 1! != 6. 1x = -
7. . , . , . , .x 2 19 0 46 1 93 0 52! ! ! !=
8. (a) , , ,x 0 90 180 360c c c c= (b) , ,x 90 180 270c c c= (c) , ,x 90 210 330c c c= (d) , , ,x 60 90 270 300c c c c= (e) , , ,x 0 180 270 360c c c c=
9. (a) , , , ,x 0 45 180 225 360c c c c c= (b) , ,x 0 180 360c c c= (c) , , , ,x 0 30 150 180 360c c c c c= (d) 45 , 60 ,135 , 120 , 225 , 240 , 315 , 300x c c c cc c c c= (e) 30 , 60 , 120 , 150 , 210 , 240 , 300 , 330x c c c c c c c c=
10.
( ) ( ) ( ) ( )
xx
x xx
x x
x xx x
33
25
3 33
23 5 3
3 2 5 33 5 3 2 0
2
2
# # #
+ ++
=
+ + ++
+ = +
+ + = +
+ - + + =
]] ]
] ]
gg g
g g
Let 3u x= +
u ub ac
5 2 04 5 4 1 2
170
2
2 2
2
- + =
- = - -
=
] ] ]g g g
So u has 2 real irrational roots. x 3` + and so x has 2 real irrational roots
Test yourself 10
1. (a) x0 3# # (b) ,n n3 31 2- (c) 2 2y ##-
2. , ,a b c1 9 14= = - = 3. (a) 2x = (b) 3-
4. ab ac1 0
42 4 1 724
0positive definite
2
# #
`
2
1
D
=
= -
= - -
= -
2] g
Answer S9-S10.indd 826 7/12/09 4:43:24 AM
827ANSWERS
5. (a) 6 (b) 3 (c) 2 (d) 18 (e) 30 6. ,x 132
31
=
7. (a) iv (b) ii (c) iii (d) ii (e) i
8.
( ) ( )
ab ac
1 04
3 4 1 47
0
2
2# #
1
1
D
= -
= -
= - - -
= -
x x4 3 02` 1- + - for all x
9. (a) 41
x = - (b) 681
10. 3 2 12 3 41x x2- + + -] ]g g 11. , ,x 30 150 270c c c=
12. (a) 341
k = (b) 1k = (c) 3k = (d) 3k = (e) 2k =
13. ,x21
3= - 14. m169
1 - 15. ,x 0 2=
16. (a) i (b) i (c) iii (d) i (e) ii
17. (a) iii (b) i (c) i (d) ii
18.
ac
kk
1
1
1
For reciprocal roots
LHS RHS
ba
ab
aa
=
=
=
= =
∴ roots are reciprocals for all x .
19. (a) 3 28 0x x2 + - = (b) 10 18 0x x2 - + =
20. 1, 3x =
21. (a) ,x x174
1 2- - (b) ,n n3 32# -
(c) y51
31
1 1 (d) ,x x10 221
2# - - (e) x4 71 #
Challenge exercise 10
1. k 4 02$D= -] g and a perfect square ∴ real, rational roots
2. y x x5 42= - + 3. , ,a b c4 3 7= = - = 4. x 2!=
5. 11 6. 2.3375n = - 7. .p 0 752 8. Show 0D =
9. x 1!=
10. 2, 19, 67 2, 13, 61A B C A B Cor= = - = = - = = -
11. 2
4 12
31
1
x x
xx x2 - -
+=
-+
+
12. ,k k2
1 212
1 21# $
- +
13. , ,x 30 90 150c c c= 14. ,x 12
3 5!=
15. , , ,x 60 90 270 300c c c c= 16. 23-
Chapter 11: Locus and the parabola
Exercises 11.1
1. A circle 2. A straight line parallel to the ladder.
3. An arc 4. A (parabolic) arc 5. A spiral
6. The straight line 2 2 | | 2x xor1 1 1-
7. A circle, centre the origin, radius 2 (equation 4x y2 2+ = i
8. lines y 1!= 9. lines x 5!= 10. line 2y =
11. Circle 1x y2 2+ = (centre origin, radius 1)
12. Circle, centre , ,1 2-^ h radius 4 13. 5y = -
14. Circle, centre (1, 1), radius 3 15. x 7= - 16. 3x =
17. y 8!= 18. x 4!=
19. Circle, centre , ,2 4-^ h radius 6
20. Circle, centre , ,4 5-^ h radius 1
Exercises 11.2
1. x y 12 2+ = 2. 2 2 79 0x x y y2 2+ + + - =
3. 10 4 25 0x x y y2 2- + + + = 4. 8 6 13 0x y- + =
5. 12 26 1 0x y- - = 6. y x!=
7. 3 32 3 50 251 0x x y y2 2- + - + =
8. 5 102 5 58 154 0x x y y2 2- + + - =
9. 4 20 36 0x x y2 - + - = 10. 20 0x y2 - =
11. 8 32 0y x2 + - = 12. 2 8 7 0x x y2 - + - =
13. 12 0x y2 + = 14. 5 2 11 0x x y y2 2- + - - =
15. 3 4 0x x y y2 2+ + - - =
16. 2 17 0x x y y2 2+ + - - =
17. 2 4 2 6 47 0x x y y2 2+ + - + =
18. 2 2 2 4 27 0x x y y2 2+ + + + =
19. 3 4 25 0, 3 4 15 0x y x y+ + = + - =
20. ,x y x y12 5 14 0 12 5 12 0- - = - + =
21. x y2 3 5 5 0!- - =
22. 7 9 0, 7 5 0x y x y- + = + - =
23. 7 4 30 0, 32 56 35 0x y x y- - = + - =
24. 16 7 40 0xy x y- - + =
25. 6 3 12 9 0x x y y2 2- - - + =
Answer S9-S10.indd 827 7/12/09 4:43:36 AM
828 Maths In Focus Mathematics Extension 1 Preliminary Course
Problem
,x y x y12 5 40 0 12 5 38 0+ - = + + =
Exercises 11.3
1. (a) Radius 10, centre (0, 0) (b) Radius 5 , centre (0, 0) (c) Radius 4, centre (4, 5) (d) Radius 7, centre (5, −6) (e) Radius 9, centre (0, 3)
2. (a) 16x y2 2+ = (b) 6 4 12 0x x y y2 2- + - - = (c) 2 10 17 0x x y y2 2+ + - + = (d) 4 6 23 0x x y y2 2- + - - = (e) 8 4 5 0x x y y2 2+ + - - = (f) 4 3 0x y y2 2+ + + = (g) 8 4 29 0x x y y2 2- + - - = (h) 6 8 56 0x x y y2 2+ + + - = (i) 4 1 0x x y2 2+ + - = (j) 8 14 62 0x x y y2 2+ + + + =
3. 18 8 96 0x x y y2 2- + + + =
4. 4 4 8 0x x y y2 2+ + + - = 5. 2 48 0x x y2 2- + - =
6. 6 16 69 0x x y y2 2+ + - + =
7. 10 4 27 0x x y y2 2- + + + = 8. 9 0x y2 2+ - =
9. 2 10 25 0x x y y2 2- + - + =
10. 12 2 1 0x x y y2 2+ + - + =
11. 8 6 22 0x x y y2 2- + - + = 12. 6 1 0x y y2 2+ + + =
13. (a) Radius 3, centre (2, 1) (b) Radius 5, centre (−4, 2) (c) Radius 1, centre (0, 1) (d) Radius 6, centre (5, −3) (e) Radius 1, centre (−1, 1) (f) Radius 6, centre (6, 0) (g) Radius 5, centre (−3, 4) (h) Radius 8, centre (−10, 2) (i) Radius 5, centre (7, −1) (j) Radius 10 , centre (−1, −2)
14. Centre ,3 1-^ h , radius 4 15. Centre ,2 5^ h , radius 5
16. Centre ,1 6- -^ h , radius 7 17. Centre (4, 7), radius 8
18. Centre ,121
1-d n , radius 221
19.
20. Show perpendicular distance from the line to ,4 2-^ h is 5 units, or solve simultaneous equations.
21. (a) Both circles have centre ,1 2-^ h (b) 1 unit
22. 2 2 23 0x x y y2 2+ + + - =
23. 56 units 24. 34 units
25. (a) 5 units (b) 3 units and 2 units (c) XY is the sum of the radii. The circles touch each other at a single point, ,0 1^ h .
26. Perpendicular distance from centre ,0 0^ h to the line is equal to the radius 2 units; perpendicular distance from centre ,1 2-^ h to the line is equal to the radius 3 units.
27. (a) 2 6 15 0x x y y2 2+ + - - = (b) , ,,2 7 1 2- -^ ^h h (c) ,Z 1 8= -^ h (d) m m
31
3
1
zx yx# #= -
= -
ZXY 90` c+ =
28. (a) 4 units (b) 4 10 13 0x x y y2 2- + + + =
Exercises 11.4
1. (a) 20x y2 = (b) 36x y2 = (c) 4x y2 = (d) 16x y2 =
(e) 40x y2 = (f) 12x y2 = (g) 24x y2 = (h) 44x y2 =
(i) 8x y2 = (j) 48x y2 =
2. (a) x y42 = - (b) 12x y2 = - (c) 16x y2 = -
(d) 28x y2 = - (e) 24x y2 = - (f) 36x y2 = -
(g) 32x y2 = - (h) 8x y2 = - (i) 60x y2 = -
(j) 52x y2 = -
3. (a) (i) (0, 1) (ii) y 1= - (b) (i) (0, 7) (ii) 7y = - (c) (i) (0, 4) (ii) 4y = - (d) (i) (0, 9) (ii) 9y = - (e) (i) (0, 10) (ii) 10y = - (f) (i) (0, 11) (ii) 11y = -
(g) (i) (0, 3) (ii) 3y = - (h) (i) (0, 121c m (ii) 1y
21
= -
(i) (i) 0, 221c m (ii) 2y
21
= - (j) (i) 0, 343c m
(ii) 3y43
= -
4. (a) (i) (0, −1) (ii) 1y = (b) (i) (0, −6) (ii) 6y = (c) (i) (0, −2) (ii) 2y = (d) (i) (0, −12) (ii) 12y = (e) (i) (0, −5) (ii) 5y = (f) (i) (0, −4) (ii) 4y = (g) (i) (0, −8) (ii) 8y = (h) (i) (0, −10) (ii) 10y =
(i) (i) 0,21
-c m (ii) 21
y = (j) (i) 0, 521
-c m (ii) 521
y =
5. (a) 28x y2 = (b) 44x y2 = (c) 24x y2 = - (d) 8x y2 = (e) 12x y2
!= (f) 32x y2!=
(g) 32x y2 = (h) 71
x y2 =
6. (a) Focus , ,0 2^ h directrix 2,y = - focal length 2 (b) Focus , ,0 6^ h directrix 6,y = - focal length 6
(c) Focus , ,0 3-^ h directrix 3,y = focal length 3
(d) Focus , ,021d n directrix ,y
21
= - focal length 21
(e) Focus , ,0 143
-d n directrix 143
,y = focal length 143
(f) Focus , ,081d n directrix ,y
81
= - focal length 81
Answer S11-S12.indd 828 7/12/09 3:09:35 AM
829ANSWERS
7. 2y = 8. ,4 4^ h 9. ,X 121
83
= - -d n 10. 4, 2-^ h and 4, 2- -^ h ; 8 units
11. (a) 12x y2 = - (b) 3y = (c) 3331
units
12. (a) Substitute the point into the equation.
(b) 3 4 3 0x y+ - = (c) ,243
-d n 13. (a) 4 2 0x y- + = (b) 0, 1^ h does not lie on the line
(c) 4 2 1 0x x y y2 2- + - + = (d) Substitute ,0 1^ h into the equation of the circle.
14. (a) Substitute Q into the equation of the parabola. (b) 1 2 2 0q x qy aq2 - - + =_ i (c) Equation of latus rectum is .y a= Solving with 4x ay2 = gives two endpoints , , ,A a a B a a2 2-^ ^h h . Length of 4AB a= .
Exercises 11.5
1. (a) 8y x2 = (b) 20y x2 = (c) 56y x2 = (d) 36y x2 = (e) 32y x2 = (f) 24y x2 = (g) 28y x2 = (h) 12y x2 = (i) 16y x2 = (j) 4y x2 =
2. (a) y x362 = - (b) 16y x2 = - (c) 40y x2 = - (d) y x242 = - (e) 8y x2 = - (f) 48y x2 = - (g) 44y x2 = - (h) y x202 = - (i) 12y x2 = - (j) 28y x2 = -
3. (a) (i) (2, 0) (ii) x 2= - (b) (i) (3, 0) (ii) 3x = - (c) (i) (4, 0) (ii) 4x = - (d) (i) (1, 0) (ii) 1x = - (e) (i) (7, 0) (ii) 7x = - (f) (i) (8, 0) (ii) 8x = - (g) (i) (6, 0) (ii) 6x = - (h) (i) (9, 0) (ii) x 9= -
(i) (i) 41
, 0c m (ii) 41
x = - (j) (i) 421
, 0c m (ii) 4x21
= -
4. (a) (i) (−2, 0) (ii) 2x = (b) (i) (−3, 0) (ii) 3x = (c) (i) (−7, 0) (ii) 7x = (d) (i) (−1, 0) (ii) 1x = (e) (i) (−6, 0) (ii) 6x = (f) (i) (−13, 0) (ii) 13x =
(g) (i) (−15, 0) (ii) 15x = (h) (i) 21
, 0-c m (ii) 21
x =
(i) (i) 621
, 0-c m (ii) 621
x = (j) (i) 141
, 0-c m (ii) 141
x =
5. (a) 20y x2 = (b) 4y x2 = (c) 16y x2 = - (d) 12y x2 =
(e) 36y x2!= (f) 8y x2
!= (g) 12y x2 = (h) 21
y x2 =
6. (a) Focus , ,2 0^ h directrix 2,x = - focal length 2
(b) Focus , ,1 0^ h directrix 1,x = - focal length 1
(c) Focus , ,3 0-^ h directrix 3,x = focal length 3
(d) Focus , ,121
0d n directrix 121
,x = - focal length 121
(e) Focus , ,141
0-d n directrix 141
,x = focal length 141
(f) Focus , ,121
0d n directrix ,x121
= - focal length 121
7. 4x = (latus rectum) 8. , , ,,12 3 6 3 6-^ ^h h 9. , ,,9 6 81 18-^ ^h h 10. (a) 5 12 25 0x y- - = (b) ,5 4
61
- -d n (c) 10125
units 2
(d) 4132
units (e) 11.7 units 2
Exercises 11.6
1. (a) yx 3 8 32- = +] ^g h (b) 5 4 6x y2- = +] ^g h (c) x y1 4 32 = +-] ^g h (d) 12x y4 32- = - -] ^g h (e) 6 8 7x y2- = +] ^g h (f) 16x y7 32+ = - -] ^g h (g) 4x y2 52- = - -] ^g h (h) 9 12 6x y2+ = +] ^g h (i) x y1 4 22+ = - -] ^g h (j) 3 8 1x y2- = +] ^g h
2. (a) 4 4 4y x2- = +^ ]h g (b) 1 8 2y x2- = +^ ]h g (c) y x2 12 12+ = +^ ]h g (d) 10 4 29y x2- = - -^ ]h g (e) 3 16 1y x2+ = - -^ ]h g (f) 6 8 4y x2- = +^ ]h g (g) 5 24 2y x2+ = - -^ ]h g (h) 12 4 36y x2+ = +^ ]h g (i) y x2 20 12- = - -^ ]h g (j) 4 8 2y x2+ = - -^ ]h g
3. (a) 2 8 9 0x x y2 + - + = (b) x x y8 4 16 02 + - + =
(c) 4 8 12 0x x y2 - - - = (d) 6 8 41 0x x y2 - - + =
(e) 4 16 20 0x x y2 + - + = (f) 2 16 1 0x x y2 + + + =
(g) x x y8 20 4 022 - + - = (h) 10 8 1 0x x y2 + + + =
(i) 6 12 45 0x x y2 + + + = (j) x y4 24 02 + + =
(k) 6 12 3 0y y x2 - - - = (l) 8 4 8 0y y x2 - - + =
(m) 8 32 0y x2 - + = (n) y y x4 16 2 012 + - =-
(o) 2 8 7 0y y x2 + - - = (p) y y x8 12 042 + + + =
(q) 2 4 11 0y y x2 - + - = (r) 6 16 25 0y y x2 - + + =
(s) 4 2 5 0y y x2 - + + = (t) y y x2 2 062 - + =-
4. (a) (i) (3, −2) (ii) 4y = - (b) (i) (1, 1) (ii) y 3= -
(c) (i) (−2, 0) (ii) 2y = - (d) (i) (4, 2) (ii) 4y = -
(e) (i) (−5, −1) (ii) 5y = - (f) (i) (3, 1) (ii) 3y =
(g) (i) (−1, 0) (ii) 4y = (h) (i) (2, 0) (ii) 2y =
(i) (i) (4, −2) (ii) 4y = (j) (i) (−2, −3) (ii) 5y =
5. (a) (i) (0, −1) (ii) 2x = - (b) (i) (2, 4) (ii) 4x = - (c) (i) (0, 3) (ii) 4x = - (d) (i) (3, −2) (ii) x 5= - (e) (i) (7, 1) (ii) 5x = - (f) (i) (1, −5) (ii) 5x = (g) (i) (11, −7) (ii) 13x = (h) (i) (−3, 6) (ii) 7x =
(i) (i) (−7, 2) (ii) 9x = (j) (i) 1021
, 3- -c m (ii) 921
x =
6. 12 36 0x y2 - + =
7. ,x x y x x y4 8 4 0 4 8 12 02 2+ - - = + + + =
8. 2 4 19 0x x y2 - - - = 9. 12 12 12 0y y x2 - + + =
10. x x y2 1 1 022 - - + = 11. 2 28 29 0x x y2 - - + =
12. 4 24 44 0y y x2 + + - = 13. 6 32 9 0y y x2 - - + =
14. 6 8 15 0x x y2 - + - = 15. 2 16 49 0y y x2 + - + =
16. 6 4 7 0x x y2 + + - = 17. 4 12 8 0x x y2 - - - =
Answer S11-S12.indd 829 7/25/09 2:27:10 PM
830 Maths In Focus Mathematics Extension 1 Preliminary Course
18. 2 16 95 0y y x2 + + - =
19. (a) Vertex ,2 1-^ h , focus ,2 3-^ h , directrix 1y = -
(b) Vertex ,3 2^ h , focus ,3 5^ h , directrix 1y = -
(c) Vertex ,1 1-^ h , focus ,1 2-^ h , directrix 0y =
(d) Vertex ,3 4^ h , focus ,7 4^ h , directrix x 1= -
(e) Vertex ,0 2-^ h , focus ,6 2-^ h , directrix 6x = -
(f) Vertex ,5 0-^ h , focus ,7 0-^ h , directrix x 3= -
20. Vertex ,1 4-^ h , focus 1, 3- -^ h , directrix 11,y = axis 1,x = - maximum value 4
21. 4 8 12 0x x y2 - - + = or 4 8 36 0x x y2 - + - =
22. (a) 8 9 72 0x y2 + - = (b) , , y0 73223
8329
=d n
23. (a)
(b) 1, 8 , y43
49
1- - = -d n
24. 4 8 20 0x x y2 + + - = 25. 0.3 m
Exercises 11.7
1. 31
m = 2. m 4= - 3. m 1= - 4. 21
m =
5. dx
dyx= 6. 2 0x y- - = 7. 2 12 0x y- + =
8. 6 0, 18 0x y x y+ - = - - =
9. 2 2 0, 2 9 0x y x y- - = + - =
10. ,,x y M 187
21
4 8 0+ - = = d n 11. , ,x y P9 0 18 27+ - = = -^ h 12. 33, 60.5Q = ^ h 13. , ,x y x y4 144 0 4 2 9 0+ + = + + = , .18 40 5-^ h ; show
the point lies on the parabola by substituting it into the equation of the parabola
14. , ,x y R4 0 4 0- - = = ^ h 15. (a) Substitute P into the equation of the parabola
(b) 2 0x py p p3+ - - = (c) Substitute 0, 1^ h into the equation of the normal.
( )Since 0, 1 0
p p pp pp p
p p
0 2 00
1
3
3
2
2!
+ - - =
= +
= +
+ =
Exercises 11.8
1. (a)
(b)
(c)
(d)
(e)
Answer S11-S12.indd 830 7/12/09 3:09:45 AM
831ANSWERS
(f)
2. (a) 2 2 0x y- - = (b) 2 11 0x y- - = (c) 3 2y x x2= + + (d) 16 1y x2= - (e) 2xy =
3. (a) ,x t y t2 2= = (b) ,x t y t6 3 2= =
(c) ,x t y t4 2 2= - = - (d) ,x t y t8 4 2= =
(e) ,x t y t18 9 2= - = - (f) ,x t y t10 5 2= =
(g) ,x t yt
32
3 2
= - = - (h) ,xt
yt
2 4
2
= =
(i) ,xt
yt
4 8
2
= = (j) ,x t yt
52
5 2
= - = -
4. (a) 16x y2 = (b) 20x y2 = (c) 4x y2 = (d) 28x y2 = - (e) 8x y2 = - (f) 4x ay2 = (g) x y42 = - (h) 24x y2 = (i) x y22 = - (j) 4x ay2 =
5. (a) Substitute ,t t6 3 2-_ i into the equation (b) ,P 12 12= - -^ h (c) 2 12 0x y- + =
6. (a) ,Q 8 4-= ^ h (b) 12 0x y- + =
7. , , x4 0 4= -^ h 8. , ; x yP 4 4 4 3 4 0= - + - =^ h
9. (a) 24x y2 = (b) 41
10. 3 18 0x y- - =
Exercises 11.9
1. (a) (i) 2
t n+ (ii)
21
4 0y t n x tn- + + =] g
(b) (i) 2
p q+ (ii) 0y p q x pq
21
2- + + =^ h
(c) (i) 2
m n+ (ii) 0y m n x mn
21
3- + + =] g
(d) (i) 2
p q+ (ii) 0y p q x pq
21
5- + + =^ h
(e) (i) 2
a b+ (ii) 0y a b x ab
21
- + + =] g
(f) (i) 2
p q-
+ (ii) y p q x pq
21
2 0+ - =+ ^ h
(g) (i) 2
a b-
+ (ii) y a b x ab
21
6 0+ - =+ ] g
(h) (i) p q
2
+ (ii) y p q x pq
21
4 0+ =- -^ h
(i) (i) 2
s t-
+ (ii) y s t x st
21
0+ - =+ ] g
(j) (i) p q
2
+ (ii) y p q x pq
21
7 0+ =- -^ h
2. (a) (i) p (ii) 1p
- (iii) 0y px p2- + =
(iv) 2x py p p3+ = +
(b) (i) q (ii) 1q- (iii) 3 0y qx p2- + =
(iv) 3 6x qy q q3+ = +
(c) (i) t (ii) 1t
- (iii) 2 0y tx t2- + =
(iv) 2 4x ty t t3+ = +
(d) (i) n (ii) 1n- (iii) 5 0y nx n2- + =
(iv) 5 10x ny n n3+ = +
(e) (i) p (ii) 1p
- (iii) 6 0y px p2- + =
(iv) 6 12x py p p3+ = +
(f) (i) − k (ii) 1k
(iii) 4 0y kx k2+ - =
(iv) 4 8x ky k k3- = +
(g) (i) q (ii) 1q- (iii) 0y qx q2- - =
(iv) 2x qy q q3+ = - -
(h) (i) − t (ii) 1t
(iii) 2 0y tx t2+ - =
(iv) 2 4x ty t t3- = +
(i) (i) m (ii) 1m- (iii) 3 0y mx m2- - =
(iv) x my m m3 63+ = - -
(j) (i) − a (ii) 1a (iii) 8 0y ax a2+ - =
(iv) 8 16x ay a a3- = +
3. (a) (i) ,p q pq+^ h (ii) ,pq p q p pq q 22 2- + + + +^ h7 A (b) (i) 4 , 4p q pq+^ h7 A (ii) ,pq p q p pq q4 4 22 2- + + + +^ _h i8 B
(c) (i) 2 , 2a b ab+] g6 @ (ii) ,ab a b a ab b2 2 22 2- + + + +] ^g h7 A (d) (i) 3 , 3s t st+] g6 @ (ii) 3 , 3st s t s st t 22 2- + + + +] ^g h7 A (e) (i) 5 , 5t w tw+] g6 @ (ii) 5 , 5tw t w t tw w 22 2- + + + +] ^g h7 A (f) (i) ,p q pq6 6+ -^ h7 A (ii) ,pq p q p pq q6 6 22 2- + - + + +^ _h i8 B
(g) (i) ,m n mn4 4+ -] g6 @ (ii) 4 , 4mn m n m mn n 22 2- + - + + +] ^g h7 A (h) (i) ,p q pq10 10+ -^ h7 A (ii) 10 , 10pq p q p pq q 22 2- + - + + +^ _h i8 B
(i) (i) ,h k hk5 5+ -] g6 @ (ii) 5 , 5hk h k h hk k 22 2- + - + + +] ^g h7 A (j) (i) 3 , 3p q pq- + -^ h7 A (ii) ,pq p q p pq q3 3 22 2+ - + + +^ _h i8 B
4. (a) (i) 4xx y y1 1= +_ i (ii) 4
y y x x x11
1- = - -_ i (b) (i) 6xx y y1 1= +_ i (ii)
6y y x x x1
11- = - -_ i
Answer S11-S12.indd 831 7/12/09 3:09:46 AM
832 Maths In Focus Mathematics Extension 1 Preliminary Course
(c) (i) 8xx y y1 1= +_ i (ii) y y x x x8
11
1- = - -_ i (d) (i) 2xx y y1 1= +_ i (ii) y y x x x
21
11- = - -_ i
(e) (i) 10xx y y1 1= +_ i (ii) y y x x x10
11
1- = - -_ i (f) (i) 2xx y y1 1= - +_ i (ii)
2y y x x x1
11- = -_ i
(g) (i) xx y y41 1= - +_ i (ii) 4
y y x x x11
1- = -_ i (h) (i) 12xx y y1 1= - +_ i (ii)
12y y x x x1
11- = -_ i
(i) (i) 22xx y y1 1= - +_ i (ii) 22
y y x x x11
1- = -_ i (j) (i) 14xx y y1 1= - +_ i (ii)
14y y x x x1
11- = -_ i
5. (a) 8xx y y1 1= +_ i (b) 2xx y y1 1= +_ i (c) 4xx y y1 1= +_ i (d) 6xx y y1 1= +_ i (e) 10xx y y1 1= +_ i (f) xx y y21 1= - +_ i (g) 12xx y y1 1= - +_ i (h) xx y y41 1= - +_ i (i) 8xx y y1 1= - +_ i (j) xx y y181 1= - +_ i
6. (a) 0y px ap2- + = (b) 2xx a y y0 0= +_ i 7.
21
2 0y t r x tr- + + =] g 8. 2 36 0x y+ - =
9.
,
yx
dx
dy x
tt
dx
dy t
t
18
9
92
9
99
At
2
2
= -
= -
- -
= --
=
e
do
n
For normal, m m 11 2 = -
mt1
2` = -
The equation is given by
( )
( )
( )
y y m x x
yt
tx t
ty t x tx t
x ty t t
29 1
9
2 9 2 92 18
2 2 9 18 0
1 12
3
3
`
- = -
+ = - +
+ = - +
= - -
+ + + =
10. 2x ty at at3+ = + 11. 3 4 4 0x y- + =
12. Substitute focus ,0 1-^ h into equation 3 4 4 0x y+ + = .
13. Equation of chord
y p q x apq21
0+ + =- ^ h
Substitute , a0^ h into equation
a apq
pq
0
1
+ =
= -
( )a p q apq
apq a
21
0 0- + + =
= -
14. ,2 1- -^ h 15. Equation of tangent at P :
0y px ap2- + = (1) Equation of tangent at Q : 0y qx aq2- + = (2)
:1 2-] ]g g
0( ) ( ) 0
( ) ( )( ) 0( ) 0
( )
px qx ap aqx q p a q p
x q p a q p q px a q p
x a q p
2 2
2 2
- + + - =
- - - =
- - + - =
- + =
= +
Substitute in (1):
( ) 000
y pa q p apy apq ap ap
y apqy apq
2
2 2
- + + =
- - + =
- =
=
16. (a) 3 4 8 0x y+ - = (b) Substitute ,0 2^ h into equation.
17. (a) For proof, see no. 9 above (b) ,N ap a0 22= +_ i 18. (a) 15 8 4 0x y+ + = (b) ,N
41
321
= - -c m 19. (a) 3 3 0x y+ - = (b) , ,6 3 2
31
-^ ch m
20. (a) ,F 0 6= ^ h
(b) 3 4 24 0x y+ - =
(c) ,Q 24 24-= ^ h (d) : 2 3 0; : 2 24 0P x y Q x y- - = + + =
(e) ,m m21
2 11 2 #= - = - ` tangents at P , Q are
perpendicular (f) 9, 6R = - -^ h (g) directrix: 6,y a= - = - R lies on directrix
21. , .P 2 1 5= - -^ h 22. 9 0x y- + =
23.
1(since 1 for focal chord)m m pq
pq1 2 =
= - = -
tangents are perpendicular
24. Tangents intersect at ,a p q apq+^ h6 @
(since for focal chord)Directrix:
y apqa pq
y a1
i.e. =
= - = -
= -
tangents meet on the directrix
25. 4
2
ya
x
dx
dy
ax
2
=
=
At , ,x yP 0 0_ i
2dx
dy
a
x0=
Answer S11-S12.indd 832 7/12/09 3:09:47 AM
833ANSWERS
The equation is given by
( )
( )
( )
( )
( )
y y m x x
y ya
xx x
ay ay x x x
xx x
xx ay x ay
ay ay xx
a y y xx
22 2
4 42 22
since
1 1
0
0
0
0 0 0
0 02
0 0 02
0
0 0
0 0
`
- = -
- = -
- = -
= -
= - =
+ =
+ =
Exercises 11.10
1. (a) 3 4 8 0x y+ - =
(b) ,Q 221
= d n
(c) (−3, −2)
(d) 4dx
dy x=
At P (−8, 8):
dx
dy
m48
21`
=-
= -
At ,q 221c m :
42
21
dx
dy
m2`
=
=
m m 2
21
1
1 2 #= -
= -
So the tangents are perpendicular.
2. (a) 0y px p2- + = (b) 1p2 + (c) ,R p0 2= -_ i and 0, 1F = ^ h 1FR p
PF
2= +
=
3. (a) 3 0y tx t2- + = (b) ,Y t0 3 2= -_ i (c) ,F 0 3= ^ h 3 1TF FY t2= = +^ h
4. (a) 5 0y qx q2+ - = (b) 0, 5R q2= _ i (c) ,F 0 5= -^ h 5 1FR FQ q2= = +_ i So triangle FQR is isosceles. FQR FRQ`+ += (base angles of isosceles triangle)
5. (a) 4 3 9 0x y+ - = (b) Focus (0, 3) Substitute into equation:
4 3 90 30
LHS
RHS
= + -
=
=
] ]g g
So it is a focal chord.
(c) Directrix y 3= - Point of intersection 8, 3= - -^ h So the point lies on the directrix.
6. 2 2x a y a2 = -^ h 7. ; ;y px p y qx q y2 0 2 0 22 2- + = - + = = -
8. x y16 62 = -^ h 9. x a y a22 = -^ h 10. (a) y a= - (b) 2x a y a2 = -^ h 11. 4 4x y2 = - +^ h 12. (a) PO has gradient
2;
p QO has gradient
2
q
m mp q
pq2 2
1
4
1 2 #
`
= = -
= -
(b) 2 4x a y a2 = -^ h (c) 2 4x a y a2 = -^ h is a parabola in the form ( ) 4x h a y k2
0- = -^ h where ,h k^ h is the vertex and a0 is the focal length
vertex is , a0 4^ h and focal length is 2a
13. 2x ay a2 2= - or 22
x a ya2 = -d n
14. (a) ,a p q apqT += ^ h6 @ (b) 6y a= -
15. (a) 5a y ax 92 = -^ h Test yourself 11
1. 8 6 29 0x y+ - = 2. 4 8 4 0x x y2 - - - =
3. Centre , ,3 1^ h radius 4 4. (a) ,1 3-^ h (b) 4, 3-^ h 5. (a) ,8 8^ h (b) 2 8 0x y- - =
6. 25x y2 2+ = 7. (a) 2y = (b) ,0 2-^ h 8. 3 10 0x x y y2 2+ + - - = 9. 8 16 16 0x x y2 - + - =
10. (a) (i) ,1 1^ h (ii) ,1 2^ h (b) 0y =
11. 2 3 6 0x y+ + = 12. 14 units
13. 24y x2 = - 14. 8 16 0x y2 - + =
15. ,x y x y4 3 16 0 4 3 14 0- - = - + =
16. ,y x y x= = - 17. 20y x2 = 18. (a) 21
- (b) 2
19. (a) 12x y2 = (b) 32y x2 = -
20. (a) 4 72 0x y- + = (b) ,9 2041d n
21. Sub ,0 4^ h: 7 0 3 4 12 0LHS RHS# #= - + = =
22. ,92
7-d n 23. 3 2 40 0x y- + =
24. 10 100 0x y2 - + = 25. 3 9 0y x a- + =
26. (a) 3 0x y- - = (b) ,R 0 3= -^ h (c) ,F FP FR0 3 6= = =^ h
Answer S11-S12.indd 833 8/2/09 3:03:59 AM
834 Maths In Focus Mathematics Extension 1 Preliminary Course
27. (a) 21
0y p q x apq- + + =^ h (b) Sub , a0^ h :
a apq
pq
0
1
+ =
= -
( )a p q apq
apq a
21
0 0#- + + =
= -
28. 2 48 0x y- + =
29. (a) 3 0x y- + = (b) ,6 9^ h and ,2 1-^ h 30. y a= -
Challenge exercise 11
1. (a) 8 6 29 0x y+ - = (b) Midpoint of AB lies on line; m m 11 2 = -
2. (a) 2 6 15 0x x y y2 2- + - - = (b) Put 0y = into equation
3. 1 2y x2= - 4. ,221
3-d n 5. (a) ;x y x y4 2 9 0 2 24 0- + = + - =
(b) 1m m1 2 = - (c) , .X 3 10 5= ^ h (d) 3 4 8 0;x y- + = focus ,0 2^ h lies on the line
6. ,0 0^ h 7. (a) ;x y x y2 4 1 0 2 4 0- - = + + =
(b) Point lies on line 1y = -
8. 2 4 2y x x2= - + - 9. 3 2 0x y+ + =
10.
11. (a) 4 10 21 0x x y y2 2+ + - + =
(b) 2 5 8;x y2 2+ + - =] ^g h centre , ;2 5-^ h 28 2radius = =
12. 3
2 3-
13. (a) 4 16 52 0y y x2 + - + = (b) 2 6 0x y- - =
14. 4 2 units 15. 2 2 0x y y2 2+ - - =
16. 696 mm from the vertex
17. ;x y x y141 127 32 0 219 23 58 0+ + = + + =
18. (a) ,Nap aq ap aq
5
6 4
5
3 22 2
=+ +f p
(b) 2 2x a y a2 = +^ h 19. 0y =
20. (a) ,T 6 20= -^ h (b) ,P t s atsa= +] g6 @
(c)
1
1
1
( )
( )
tan
tan
m t m s
m m
m m
tst s
tst s
tst s
ts t ss t ts
t s
ss
t
tst s
ts t ss t ts
t s
ss
t
45
1
11
11
1
11
11
11
1
11
and
or
1 2
1 2
x y
c
i
= =
=+
-
=+
-
=+
-
=+
-
+ = -
+ = -
= -
-
+=
- =+
-
- - = -
- = +
= +
+
-=
Practice assessment task set 3
1. ≤ , ≥m m2 3 2. 4 3 16 0x y+ - = 3. 8x y2 =
4. 24 cm 5. Centre , ,3 5-^ h radius 7
6. (a) 32
(b) 31
- (c) 191
7. Focus , ,0 2-^ h directrix 2y =
8. 5x = - or 6- 9. 1k = -
10.
180
( equal to opp. interiorin cyclic quadrilateral)
( s supplementary in cyclicquadrilateral)
AFE CBE
CBE EDC
AFE EDC180
ext.
opp.
`
c
c
+ +
+ +
+ +
+
+
+
=
= -
= -
These are supplementary cointerior angles. | CD|AF`
11. ,x y x y3 4 14 0 3 4 16 0- - = - + =
12. Vertex ,4 17- -^ h , focus , .4 16 75- -^ h 13. ,x 0 3= 14. 7.2k cm= 15. 2 2 0x y+ + =
16. b 2$ - 17. 16ci = 18. 16,x y2 2+ = circle centre ,0 0^ h and radius 4
19. 4 6 12 0x x y y2 2+ + + - =
Answer S11-S12.indd 834 7/12/09 3:09:49 AM
835ANSWERS
20. x x y y3 6 17 02 2- + - - =
21. ( in semicircle)(similarly)
( s in same segment)( sum of )
BCDDABDBC DAEBDC DBC BDCBDC DAEDAE BDC
9090
909090
`
`
cc
ccc
+ +++ + ++ + ++ ++ +
D
=
=
=
= -
= -
= -
22. 0.75- 23. 5 54 5 20 79 0x x y y2 2- + + - =
24. , ,a b c2 1 0= = = 25. °, °x y33 57= =
26. 9 x
x2
--
27. (a) 0y px ap2- + = (b) ,Rp
pa
a 12
=-
-_f i p
(c) 2 1 0px p y a ap2 2+ - + - =_ i
28. 4 16 20 0x x y2 - - + =
29. and (given)
(vertically opposite angles)
AC BC CD CE
CDAC
CEBC
ACB ECD
`
+ +
= =
=
=
since two sides are in proportion and their included angles are equal, Δ ABC is similar to Δ CDE 5.3 cmy =
30. 4 0x y- - =
31. 2 16 15 0x x y2 + - - = 32. ,x 0 2=
33. 04
1 4( 1)( 9)35
0
ab ac2
2
1
1
D = -
= - - -
= -
Since a 01 and 0, 9 0x x21 1D - + - for all x
34. ( )( ) ( )x x x8 3 2 5 3 2 51 3 4+ + +- ( )x x30 7 2 5 3= + +] g
35. sec cosecx x
36.
Let ABCD be a cyclic quadrilateral of circle, centre O . Join AO and CO .
Obtuse 2Reflex
( at centre double at circumference)AOC ADCAOC ABC2 (similarly)
+ ++ +
+ +=
=
Obtuse reflex
It can be proved similarly that
by drawing and .
( of revolution)AOC AOCADC ABC
ADC ABC
BAD BCDBO DO
3602 2 360
180
180
`
ccc
c
+ ++ ++ +
+ +
++ =
+ =
+ =
+ =
opposite angles in a cyclic quadrilateral are supplementary
37. Centre , ,5 3-^ h radius 2
38. ( , )
( )( )
( )( )
DBA x EBC yEDB x DEB yFDE xGED yFGB DBA xGFB EBC yFDE FGBGED GFB
DE ACFDBGEB
180180
180180
Let andThen and
and
alternate sstraightstraight
s in alternate segmentsimilarly
`
cc
cc
+ ++ ++++ ++ ++ ++ +
+
+ +
+ +
+
<
= =
= =
= -
= -
= =
= =
= -
= -
Since opposite angles are supplementary, FGED is a cyclic quadrilateral.
39.
( )( )
ab ac0
41 4 1 3
110
2
2
2
1
D = -
= - -
= -
] g
Since 0a 2 and ,01D x x 3 02 2- + for all x
40. 1k = 41. 3 2 9 0x y+ - =
42. (a) 217 km (b) 153c
43. , ,a b c3 18 34= = - = - 44. ,x x4 32 1
45. (a) 1y x2= - (b) ,4 15-^ h (c) 8 124 0x y- + =
46. ’95 44ci = 47. x 11c=
48. 361 0 and a perfect squareT 2= ^ h 49. 2 9 0x y+ + = 50. k 3#
51.
52. 5 4 41 0x y- - = 53. ,352
252
-d n 54. 3 1
1 3
-
+
55. y141
11#- - 56. 22
3 6 10 3 3 5- + -
Answer S11-S12.indd 835 7/25/09 2:27:11 PM
836 Maths In Focus Mathematics Extension 1 Preliminary Course
57. 4.9 , 11.1x ycm cm= = 58. 1x = 59. 8.25 units
60. 4.5 m 61. 2187128
62. °, °, °, °x 60 120 240 300=
63. 2 3 3 0x y+ - = 64. ,y 131
21
= - 65. 162c
66. 9090
( semicircle)( straight )
ACBDCA DCB
in`
c
c
++
+
+ +
=
=
AD is a diameter of the circle
67. °, °, °, °x 45 135 225 315=
68. 1, 2 or , 4x y x y41
41
= - = = - =
69. a b a ab b2 2 42 2+- +] ^g h 70. 43x = 71. 311
-
72. 1.8 units 73. tan i
74. 8 2 5 ( 1) 2( 1)x x x x2 3 2 4+ - + -] g ( ) ( )x x x2 1 9 20 12 3 2= - + -
75. 41
76. 2 3 25 0x x y y2 2+ + - - =
77. Focus (2, 1), directrix 5y =
78. 9 0px y p2- - = 79. 2 36 0x y- - =
80. (a) 21
0y p q x apq- + + =^ h (b) 2 2x a y a2 = -^ h (c) Concave upward parabola, vertex (0, 2 a )
81. (c) 82. (d) 83. (b) 84. (a) 85. (c) 86. (a)
87. (c) 88. (a) 89. (a), (d) 90. (c)
Chapter 12: Polynomials 1
Exercises 12.1
1. (a) 7 (b) 4 (c) 1 (d) 11 (e) 3 (f) 0 (g) 4
2. (a) 19- (b) 10- (c) 1- 3. (a) 6- (b) 5 (c) 2 (d) 1 (e) 2 4. (a) 5 (b) 4 (c) 3- (d) 0
5. (a) 3! (b) 5- (c) ,2 1- (d) 4 (e) 0
6. (a) ;P x x x x12 6 2 4 33 2= - - +l ] g (b) ;P x x10 1=l] g (c) ;P x x x108 35 8 1111 4= - +l] g (d) ;P x x x x7 9 2 7 66 2= - + -l ] g (e) 8; 0P x =l] g
7. (a), (b), (g) 8. (a) 0a = (b) 10b = (c) c 6= -
(d) a 1= - (e) 4a = 9. (a) 221
- (b) ,x 2 1= -
(c) 3 (d) 3 (e) x5
10. (a) b ac48
8 0
2
1
D = -
= -
-
f x` ] g has no zeros
(b) 9x3 (c) 2- (d) 9 (e) ,x32
1= -
11. (a) 2 (b) 0 (c) 2 (d) 0 (e) 2 (f) 4 (g) 3
12. ,x 3 2= - 13. 0, 1x =
14. P x x x3 2 92= - +l] g b ac4 104 02 1- = -
So ( )P xl has no real roots
15. Q x x x3 6 32= - +l] g 4 0b ac2 - =
So Q xl] g has equal roots
Exercises 12.2
1. 3 2 5 4 3 10 45x x x x2 + + = + - +] ]g g
2. 7 4 1 6 2x x x x2 - + = - - -] ]g g
3. 2 1 3 4 14 41x x x x x x3 2 2+ + - = - + + +] ^g h
4. 4 2 3 2 3 2 2 3x x x x2 + - = + - +] ]g g
5. 5 2 3 8 25 2x x x x x x x3 2 2- + + = + - + +^ ] ]h g g 6. 3 2 3 5 7x x x x x x3 2 2+ - - = - + + +] ^g h
7. 5 2 3 1 5 7 10 1x x x x x x x3 2 2- + + = + - + +^ ] ]h g g 8. 2 3
281x x x x
x x x x4 5 18 71
4 3 2
3 2
- - + -
= + - + - +] ^g h
9. 2 5 2 2 5 2 2 2 5x x x x x x x x x4 3 2 2 2- + + - = - - + -^ ^ ]h h g 10. 4 2 6 1 2 1 2 2 4 5x x x x x x3 2 2- + - = + - + -] ^g h
11. 6 3 1 3 2 231
132
x x x x2 - + = - + +] dg n
12. x x x x x x x x2 2 2 2 24 3 2 2 2- - - = - - - + - -^ ^ ]h h g 13. 3 2 3 1x x x x x
x x x x x2 3 8 13 25 49 99
5 4 3 2
4 3 2
- - + - -
= + - + - + -] ^g h
14. 5 2 1 4 6x x x x2 + - = + + -] ]g g
15. 2 5 4 3 3 7 26 82x x x x x x x4 2 3 2- + + = - + + + +] ^g h
16. 2 5 2 2 3 6 12 5x x x x x x x4 3 2 2- + = - + + + +^ ^ ]h h g 17. 3 3 1 5 3 2 14x x x x x x3 2 2- + - = + - + - +^ ] ]h g g 18. 2 4 8 3 2 2 2 12x x x x x x x3 2 2+ - + = + + - + +^ ] ]h g g 19. 2 4 2 5x x x x
x x x x x2 1 4 13 28 18
4 3 2
2 2
- + + +
= + - - + + - +^ ^ ]h h g
20. 3 2 1 1 3 3 2 3x x x x x x x x5 3 4 3 2- + - = + - + - + -] ^g h
Exercises 12.3
1. (a) 41 (b) 3- (c) 43- (d) 9424 (e) 0 (f) 37 (g) 47 (h) 2321 (i) 31 174 (j) 3-
2. (a) 8k = (b) 72
k = (c) k 15 299= (d) k9
68
= (e) k 2!=
3. (a) 0 (b) Yes (c) 4 6 2 2 3x x x x x x3 2 2- + + = - - -] ^g h (d) 2 3 1f x x x x= - - +] ] ] ]g g g g
Answer S11-S12.indd 836 7/25/09 2:27:11 PM
837ANSWERS
4. (a) 3 81 81 81 81 0P - = - - + =] g x 3` + is a factor (b) P x x x x3 32= + -] ] ]g g g
5. ,a b1127
14817
= - = - 6. 6a = -
7. (a) P 3 140 0!=] g x 3` - is not a factor of P x] g (b) 39k = - 8. ,a b2 1= - = -
9. (a) ,a b3 11= = (b) 1 3 8 7 2f x x x x x3 2= + + + +] ] ^g g h (c) g 1 0- =] g (d) 3 2 1f x x x 3= + +] ] ]g g g
10. (a) 2 4x x+ -] ]g g (b) 2 1x x x+ -] ]g g (c) 1 4 2x x x- + -] ] ]g g g (d) 5 3 2x x x+ - +] ] ]g g g (e) 3 1 7x x x- - -] ] ]g g g (f) 2 9 5x x x+ - -] ] ]g g g (g) 3 2x x 2- -] ]g g (h) x x x4 1 2+ +] ]g g (i) 1 2x x 2- +] ]g g (j) 1 3 2x x x+ - +] ] ]g g g
11. (a) 1 3 2P x x x x= - + -] ] ] ]g g g g (b) , ,3 1 2- (c) Yes
12. (a) Dividing f x] g by 5 2x x+ -] ]g g gives 5 2 7 12f x x x x x2= + - + +] ] ] ^g g g h x x5 2` + -] ]g g is a factor of f x] g (b) 5 2 3 4f x x x x x= + - + +] ] ] ] ]g g g g g
13. 1 4 3P x x x x 2= + - +] ] ] ]g g g g 14. (a) P P6 5 0- = =] ]g g (b) 4 6 5P x x x x= - + -] ] ] ]g g g g 15. (a) P u u u2 1 2= - -] ] ]g g g (b) 2, 3x =
16. (a) 1 2 3f p p p p= - + -^ ^ ^ ^h h h h (b) , ,x 0 121
1= -
17. (a) 2 1 1P k k k 2= - +] ] ]g g g (b) , ,x 30 150 270c c c=
18. (a) 1 3 9f u u u u= - - -] ] ] ]g g g g (b) 0, 1, 2x =
19. , ,x 5 4 2= - - -
20. , , , , ,0 90 120 240 270 360c c c c c ci =
21. (a) , , ,a b c d1 3 4 2= = = = - (b) , , ,a b c d1 1 8 12= = - = = - (c) , , ,a b c d2 0 1 6= = = - = (d) , , ,a b c d1 1 11 12= = = = - (e) , , ,a b c d3 0 1 8= = = - = (f) , , ,a b c d1 1 4 7= = = - = - (g) , , ,a b c d5 2 19 43= = - = - = - (h) , , ,a b c d1 4 1 1= - = = - = - (i) , , ,a b c d1 3 6 4= - = = = - (j) , , ,a b c d1 10 27 20= - = - = - = -
22. 12P x x x x3 2= - -] g 23. , ,a b c1 3 6= = - = -
24. 2 4 10 12P x x x x x4 3 2= - - +] g
25. P ( x ) has degree 3. Suppose P ( x ) has 4 zeros, a 1 , a 2 , a 3 and a 4 . Then x a x a x a x a1 2 3 4- - - -_ _ _ _i i i i is a factor of P ( x ) . So P x x a x a x a x a Q x1 2 3 4= - - - -] _ _ _ _ ]g i i i i g . P ( x ) has at least degree 4 But P ( x ) only has degree 3. So it cannot have 4 zeros .
Exercises 12.4
1. (a) y
x- 21 3
6
(b)
y
x-4 2
(c) y
x1 3
(d) y
x-2
Answer S11-S12.indd 837 7/25/09 2:27:12 PM
838 Maths In Focus Mathematics Extension 1 Preliminary Course
(e)
2. (a) (i) 4 2P x x x x= - +] ] ]g g g
(ii)
(b) (i) 1 5f x x x x= - - +] ] ]g g g (ii)
y
x-5 1
(c) (i) 1 2P x x x x2= + +] ] ]g g g (ii) y
x-1-2
(d) (i) 2 5 3A x x x x= - +] ] ]g g g (ii)
(e) (i) 3 1P x x x x2= - - +] ] ]g g g (ii) y
x-1 3
3. (a) , ,x 0 1 2= -
(b) y
x-2 1
4. (a) P 2 8 12 8 120
= - - +
=
] g
(b) 2 3 2P x x x x= - - +] ] ] ]g g g g (c) y
x-2 2 3
12
y
x-2 5
50
-5
y
x21
2-3
y
x-2 4
Answer S11-S12.indd 838 7/12/09 3:18:58 AM
839ANSWERS
5. (a) y
x-4 -2
-24
3
(b) y
x-3 -1
-9
3
(c) y
x
12
1 3 4
(d) y
x
12
1 3-4
(e) y
x2 3-3
-18
(f) y
x2-2
-8
(g) y
x1 2
-4
(h) y
x1
3
-3
Answer S11-S12.indd 839 7/12/09 3:22:46 AM
840 Maths In Focus Mathematics Extension 1 Preliminary Course
(i) y
x4-2
(j) y
x
1
1-1
Exercises 12.5
1. (a) 3,x = double root (b) 0, 2, 7,x = single roots (c) 0,x = double root, 3,x = single root (d) 2,x = - single root, 2,x = double root (e) 2,x = - triple root (f) , ,x 0 2= single roots,
1,x = double root (g) 1, 3,x = - double roots (h) 0,x = triple root, 4,x = double root (i) 1,x = triple root, 5,x = -
single root (j) 121
,x = triple root
2. (a) (i) Positive (ii) Even (b) (i) Negative (ii) Odd (c) (i) Negative (ii) Even (d) (i) Negative (ii) Odd (e) (i) Positive (ii) Odd (f) (i) Positive (ii) Even (g) (i) Positive (ii) Odd (h) (i) Negative (ii) Even (i) (i) Positive (ii) Odd (j) (i) Positive (ii) Even
3. P x x 4= +2] ]g g Yes, unique
4. (a) P x k x 1= -3] ]g g Not unique (b) 5 1P x x 3= -] ]g g
5. (a) 4 8 16x x x2 2- = - +] g Dividing by 8 16x x2 - + gives 7 8 16 8 16 1x x x x x x3 2 2- + + = - + +^ ]h g so x 4-
2] g is a factor (b) 1 4P x x x 2= + -] ] ]g g g
(c) 4 4 1 4 4P 2= + -] ] ]g g g 0=
( )( ) ( )
P x x xP
3 14 84 3 4 14 4 8
0
2
2
= - +
= - +
=
l
l ] g
6. (a) x x x x3 9 27 273+ = + + +3 2] g
Dividing by 9 27 27x x x3 2+ + + gives 7 9 27 54 9 27 27 2x x x x x x x x4 3 2 3 2+ + - - = + + + -^ ]h g so x 3 3+] g is a factor (b) f x x x2 3= - + 3] ] ]g g g (c) f 3 3 2 3 3- = - - - + 3] ] ]g g g 0=
( )
( ) ( )f x x x x
f4 21 18 27
3 4 3 21 3 18 3 270
3 2
3 2
= + + -
- = - + - + - -
=
l
l ] ]g g
7. (a) P x x k Q x3= -] ] ]g g g where Q ( x ) has degree 3n - (b) P k k k Q k3= -] ] ]g g g 0=
( )P xl u v v u= +l l
( )P kl ( ) ( )( ) ( )
Q x x k x k Q xQ k k k k k Q k
33
0
3 2
3 2
= - + -
= - + -
=
l
l
] ]] ]
g gg g
8. (a) y
x
(b) y
x
Answer S11-S12.indd 840 7/12/09 3:22:47 AM
841ANSWERS
(c) y
x
(d) y
x
(e)
y
x
9. y
x2
10. y
x-1
11. y
x2
12. y
x-3
13. y
x1
Answer S11-S12.indd 841 7/12/09 3:22:48 AM
842 Maths In Focus Mathematics Extension 1 Preliminary Course
14. y
x
15. y
x-2
16. y
x4
17. Odd function with positive leading coeffi cient starts negative and turns around at the double root. It then becomes positive as x becomes very large so it must cross the x -axis again. So there is another root at k 12 -
k
y
x-1
18. Even function with negative leading coeffi cient is negative at both ends. The triple root has a point of infl exion so the curve must cross the x -axis to turn negative again. So there is another root at k 22 -
y
xk-2
19. Odd function with positive leading coeffi cient starts negative and turns around at both the double roots. It then becomes positive as x becomes very large so it must cross the x -axis again. So there is another root at k 22
y
xk-3 2
Answer S11-S12.indd 842 7/12/09 3:22:48 AM
843ANSWERS
20. Odd function with negative leading coeffi cient starts positive and turns around at the double root. It then becomes negative as x becomes very large so it must cross the x -axis again. So there is another root at k 12
y
xk1
Exercises 12.6
1. (a) (i) 2 (ii) 8 (b) (i) 2- (ii) 32
- (c) (i) 7- (ii) 1
(d) (i) 241
(ii) 3- (e) (i) 3- (ii) 0 2. (a) (i) 1- (ii) 2-
(iii) 8- (b ) (i) 3 (ii) 5 (iii) 2 (c) (i) 21
(ii) 3
(iii) 1- (d) (i) 3- (ii) 0 (iii) 11- (e) (i) 0 (ii) 7 (iii) 3
3. (a) (i) 2- (ii) 1- (iii) 1 (iv) 5 (b) (i) 1 (ii) 3-
(iii) 2- (iv) 7- (c) (i) 1 (ii) 3- (iii) 2- (iv) 4-
(d) (i) 1 (ii) 2- (iii) 121
- (iv) 1- (e) (i) 6 (ii) 0
(iii) 0 (iv) 321
4. (a) 5 (b) 5- (c) 1- (d) 35
(e) 200 5. (a) 23
(b) 21
- (c) 25
- (d) 31
-
(e) 21
-
6. (a) 3- (b) 5- (c) 132
7. 26k = -
8. ,2 7a b ab+ = = - 9. ,221
21
a b ab+ = = -
10. (a) 0k = (b) 4k = (c) ±1k = (d) ,k21
1= -
(e) 0k = 11. m 9= - 12. ,a b183
941
= - = -
13. (a) 1 0P =] g (b) ,1 6a b c abc+ + = = -
14. ;a 1 2a b= + = - 15. (a) 154
(b) ,p q8154
17152
= = - 16. 1 17. 5-
18. ,x21
121
= - 19. ,x31
21
!= 20. , ,x 3 121
32
!= -
Test yourself 12
1. 3 3 5 1p x x x x x= + - + -] ] ] ] ]g g g g g 2. (a) 3 (b) 9 (c) 1 (d)
91
3. ( ) ( ) ( )( )P x x x xx x x
6 1 25 8 123 2
= - - +
= - - +
4. (a) 3 2x x2 + + (b) 5 3 1 2p x x x x x= - + + +] ] ] ] ]g g g g g 5. (a) 3 (b) 3- (c) , ,3 0 1- (d) x3
6.
7. (a) 3a = (b) 5-
8. ( ) ( )p 7 7 7 7 5 7 4725 0
3 2
!
- = - - - + - -
= -
] ]g g
9. ,x 1 3!= - 10. , ,a b c2 18 40= = - =
11. x -intercepts , , ;3 2 4- y -intercept 24
12. ( ) ( )
x x xx x x x x
3 7 8 52 3 6 5 18 36 67
5 3 2
4 3 2
- + -
= - + + + + +
13. 60 , 90 , 180 , 270 , 300x c c c cc= 14. 7.4k =
15. 4, 5
16.
17. 14k = - 18. 4
Answer S11-S12.indd 843 7/12/09 3:22:49 AM
844 Maths In Focus Mathematics Extension 1 Preliminary Course
19. ( ) ( )
( ) ( ) ( )( ) ( ) ( )
P a A a a a
P x A x x a A x x aP a A a a a A a a a
033
0
3
2 3
2 3
= -
=
= - + -
= - + -
=
l l
l l
]] ]] ]
gg gg g
20. f 5 5 6 5 12 5 35 03 2= - + - =] ] ]g g g
21. (a) f 5 5 7 5 5 5 753= - - +2] ] ]g g g 0=
(b) f x x x3 14 52= - -l] g
( ) ( )f 5 3 5 14 5 50
2= - -
=
l ] g
(c) Double root at 5x = (d) f x x x3 5= + - 2] ] ]g g g
22.
3
y
x
23. (a) P x x Q x6= + 3] ] ]g g g (b) y
x-6
24. y
x
25. (a) , , ,a b c d2 3 4 5= = - = =
Challenge exercise 12
1. 1 1 1P x x x x x2 2= - + + +] ] ] ^g g g h 2. (a) ( ) ( )
( ) ( ) ( )( ) ( ) ( )
P b b b Q b
P x x b Q x Q x x bP b b b Q b Q b b b
077
0
7
7 6
7 6
= -
=
= - + -
= - + -
=
l l
l l
]] ]] ]
gg gg g
(b) ,a b 17= - = -
3. , , , , , , , ,0 45 60 120 180 225 240 300 360c c c c c c c c ci =
4. (a) 3 2 0x y- + = (b) ,2 8^ h 5. (a) 4
33a -
(b) a 14= -
6. (a) 3- (b) 17 7. 90 , 210 , 330c c ci = 8. 5a = -
9. If x a- is a factor of P x] g
( ) ( ) ( )( ) ( ) ( )
P x x a Q xP a a a Q a
0
Then`
= -
= -
=
10. , , ,1 1 3 5- - -^ ^h h 11. P x x x1 2= - + -2 3] ] ]g g g
12. y
xa1 a2
Answer S11-S12.indd 844 7/12/09 3:22:50 AM
845ANSWERS
Chapter 13: Permutations and combinations
Exercises 13.1
1. 10 000
1 2.
3316
3. 92
4. 20 000
1
5. 98.5% 6. (a) 74
(b) 73
7. 203
8. 31
9. (a) 61
(b) 31
(c) 65
10. (a) 621
(b) 313
(c) 21
(d) 12499
11. (a) 151
(b) 158
(c) 53
12. 8
13. (a) 8629
(b) 4319
(c) 8667
14. 32
15. (a) 61
(b) 21
(c) 31
(d) 21
(e) 21
16. (a) 185
(b) 91
17. (a) 54
(b) 36 18. (a) 4423
(b) 4421
19. 196
20. 982329
21. (a) 3119
(b) 3120
(c) 314
(d) 1131
22. (a) 5914
(b) 5935
(c) 2459
(d) 5938
23. 245
24. 19% 25. 0.51
Exercises 13.2
1. 456 976 2. 67 600 3. 26 105 4# 4. 260
5. 26 1010 15# 6. 1 000 7. 1 000 000
8. 300 9. 64 10. 10 000
3
11. (a) 84 (b) 841
12. (a) 10 000 000 (b) 1000
13. Yes 14. 67 600 000
1 15. 7 16. Yes
17. 5184
1 18. 6 19. 6840 20. 360
21. 7 880 400 22. 210 23. 271 252 800
24. (a) 9900 (b) 9900
1 25.
7201
Exercises 13.3
1. (a) 720 (b) 3 628 800 (c) 1 (d) 35 280 ( e) 120 (f) 210 (g) 3 991 680 (h) 715 (i) 56 (j) 330
2. 362 880 3. 720 4. 479 001 600 5. 120
6. (a) 39 916 800 (b) 479 001 600 7. 40 320
8. 5040 9. 6 10. 720 11. 5040
12. 1.3 1012# 13. (a) 39 916 800 (b) 3 628 800
14. (a) 720 (b) 120 (c) 48 15. 5040
16. (a) 41
(b) 241
17. (a) 479 001 600 (b) 121
18. 120
1
19. 6 227 020 800
20. (a) !! 8 7 6 ... 2 1
48
4 3 2 18 7 6 5
# # #
# # # # #
# # #
=
=
(b) !! 11 10 9 ... 2 1
611
6 5 4 3 2 111 10 9 8 7# # # # #
# # # # #
# # # #
=
=
(c) .
.
.
.!!
...
... ...
...( 1)( 2) ... ( )
rn
r r r
n n n r r r
n n n rn n n r
1 2 3 2 1
1 2 1 1 3 2 1
1 2 11
# # # #
# #
=- -
- - + -
= - - +
= - - +
] ]] ] ] ]] ] ]
g gg g g gg g g
(d) . .
. .
!!
...
... ...
...n r
nn r n r n r
n n n n r n r
n n n n r1 2 3 2 1
1 2 1 3 2 1
1 2 1-
=- - - - -
- - - + -
= - - - +
] ] ] ]] ] ] ]] ] ]
g g g gg g g gg g g
Exercises 13.4
1. (a) 6 3 !
6!120
-=] g (b)
5 2 !5!
20-
=] g (c) 8 3 !
8!336
-=] g
(d) !
!10 7
10640 800
-=] g (e)
!!
9 69
60 480-
=] g
(f) 7 5 !
7!2520
-=] g (g)
!!
8 68
20 160-
=] g
(h) !
!11 8
116 652 800
-=] g (i)
9 1 !9!
9-
=] g
(j) 6 6 !
6!720
-=] g
2. (a) 650 (b) 15 600 (c) 358 800 (d) 7 893 600
3. (a) 648 (b) 432 (c) 144 4. (a) 20 (b) 4 (c) 12 (d) 8
5. (a) 24 (b) 24 6. (a) 4536 (b) 2016 (c) 3528
7. (a) 120 (b) 48 (c) 96 (d) 72 (e) 60
8. (a) 479 001 600 (b) 1320
9. (a) 56 (b) 336 (c) 1680
10. (a) 60 480 (b) 2520 (c) 907 200 (d) 151 200 (e) 60 (f) 453 600 (g) 360 (h) 2520 (i) 59 875 200 (j) 90 720
11. (a) 24 (b) 5040 (c) 40 320 (d) 3 628 800 (e) 39 916 800
12. (a) 6 (b) 720 (c) 5040 (d) 362 880 (e) 3 628 800
Answer S13.indd 845 7/25/09 2:38:37 PM
846 Maths In Focus Mathematics Extension 1 Preliminary Course
13. (a) 181 440 (b) 19 958 400 (c) 20 160 (d) 1 814 400 (e) 239 500 800
14. (a) 720 (b) 120 15. (a) 362 880 (b) 40 320
16. (a) 3 628 800 (b) 362 880 (c) 181 440
17. (a) 24 (b) 12 (c) 24
18. (a) 720 (b) 240 (c) 480 (d) 144
19. (a) 3 628 800 (b) 362 880 (c) 28 800
20. 92
21. (a) 20! (b) 5!8!7!3! (c) 207
22. (a) 60 (b) 48 (c) 36 (d) 51
23. 16
24. 1
336 25. (a) 40 320 (b) 30 240 (c) 21 600
26. (a) 20 (b) 60 27. (a) 720 (b) 120 (c) 192
28. (a) x ! (b) 1 !x -] g (c) 2! 2 !x -] g (d) ! !x3 2-] g (e) 3 2 !x x- -] ]g g
29. (a) ! !
!!
!!
!
P
3 38 3
8
58
3
8
3
'
=-
=
] g
8
8 8
!!
!
! !!
! !!
!
!!
!
!!
!
! !!
! !
P
P P
58
31
5 38
5 58 5
8
38
5
38
51
5 38
3 5
5
3 5
#
'
#
=
=
=-
=
=
=
` =
] g
(b)
n
! !!
!
!!
!
!!
!
! !!
! !
( ) !!
r
P
rn rn
n rn
r
n rn
r
n r rn
n r
P
n r
n n rn
1
n
r
n r
'
#
=-
=-
=-
=-
-=
-
- --
]
]
]
]
] ]
g
g
g
g
g g5 ?
`
n n
!!
( ) !
!!
!
! !!
! !
n n rn
n r
rn
n r
n r rn
r
P
n r
P
1
r n r
'
#
=- +
-
=-
=-
=-
-
]
]
]
]
g
g
g
g
30. n
n
n
1+
n
!
!
!!
!
!
!!
!
!
!!
!!
!
!
!!
!
!
!!
!! ! ! !
!! !
!
!
!
!
Pn r
n
P r Pn rn
rn r
n
n rn
rn r
n
n rn
n rrn
n r n r
n r n
n rrn
n r
n r n
n rrn
n rn n n rn rn
n rnn n
n r
n n
n r
n
P P r P
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
r
rn
r
n
r r r
1
1
1
$
`
=+ -
+
+ =-
+- -
=-
+- -
=-
+- +
=+ - -
+ -+
+ -
=+ -
+ -+
+ -
=+ -
+ - +
=+ -
+
=+ -
+
=+ -
+
= +
-
+
-
]]
] ^] ^] ]
] ]]
]
]]
]
]
]
]]
]]
gg
g hg hg g
g gg
g
gg
g
g
g
gg
gg
5
5
?
?
Exercises 13.5
1. (a) 9 5 !5!
9!126
-=] g (b)
12 7 !7!12!
792-
=] g
(c) ! !
!8 3 3
856
-=] g (d)
10 4 !4!10!
210-
=] g
(e) 11 5 !5!
11!462
-=] g
2. (a) (i) 1 (ii) 1 (iii) 1 (iv) 1 (v) 1 (b) (i)
nC 10 = (ii)
nC 1n =
3. (a) 28 (b) 84 (c) 462 (d) 5005 (e) 38 760
4. (a) Number of arrangements 15=
R1R2 R2R3 R3B1 B1B2 B2B3
R1R3 R2B1 R3B2 B1B3
R1B1 R2B2 R3B3
R1B2 R2B3
R1B3
(b) 77 520
Answer S13.indd 846 7/11/09 2:47:39 PM
847ANSWERS
5. 15 504 6. 210 7. 2 598 960
8. (a) 720 (b) 120 9. (a) 2184 (b) 364
10. 296 010 11. 4845 12. 2925
13. 23 535 820 14. (a) 792 (b) 125
(c) 335
15. (a) 100 947 (b) 462 (c) 924 (d) 36 300 (e) 26 334 (f) 74 613 (g) 27 225
16. $105
17. (a) 2 042 975 (b) 55 (c) 462 462 (d) 30 030
18. (a) 3003 (b) (i) 2450 (ii) 588 (iii) 56 (iv) 1176
19. (a) 1.58 1010# (b) 286 (c) 15 682 524 (d) 5 311 735
(e) 12 271 512
20. (a) 395 747 352 (b) 32 332 300 (c) 4 084 080 (d) 145 495 350 (e) 671 571 264
21. (a) 170 544 (b) 36 (c) 20 160 (d) 17 640 (e) 6300
22. (a) 7 (b) 27 132 (c) 13 860 (d) 20 790 (e) 27 720
23. (a) 5 (b) 360 (c) 126
24. (a) 792 (b) 792
(c) 12
12
12
! !!
! !!
! !!
! !!
C
C
C C
12 5 512
7 512
12 7 712
5 712
5
7
125 7`
=-
=
=-
=
=
]
]
g
g
25. 9
8
9
8
8 8
C
C C
C C C
84
28 5684
6
6 5
6 6 5`
=
+ = +
=
= +
26. ! !
!
! !!
! !!
! !!
137 13 7 7
13
6 713
136 13 6 6
13
7 613
137
136`
=-
=
=-
=
=
b ]
b ]
b b
l g
l g
l l
27. ! !
!
! !!
! !!
! !!
! !!
! !!
! !!
! !!
! !!
! !!
! !! !
! !!
! !!
104 10 4 4
10
6 410
94
93 9 4 4
99 3 3
9
5 49
6 39
6 5 46 9
4 6 34 9
6 46 9
6 44 9
6 46 9 4 9
6 410 9
6 410
104
94
93
#
#
#
#
# #
# #
#
`
=-
=
+ =-
+-
= +
= +
= +
=+
=
=
= +
b ]
b b ] ]
b b b
l g
l l g g
l l l
28. ! !
!
( ) ! !!
! !!
! !!
nr n r r
n
nn r n n r n r
n
n n r n rn
r n rn
nr
nn r`
=-
-=
- - -
=- + -
=-
=-
b ]b ]
] ]
]b b
l gl g
g g
gl l
5 ?
29.
!r
!r
n
!!
!! !
!
!!
Pn rn
C rn r r
n
n rn
P
r
nr
nr
nr
#
`
=-
=-
=-
= C
]
]
]
g
g
g
30. ! !
!nk n k k
n=
-b ]l g
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !!
nk
nk n k k
n
n k k
n
n k k
n
n k k
n
k n k k
k n
n k n k k
n k n
n k k
k n
n k k
n k n
n k k
k n k n
n k k
n n
n k kn
nk
11
11 1 1
1
1
1
1
1
1
1
1
1
1
1
1 1
1
1
--
+-
=- - - -
-+
- -
-
=- -
-+
- -
-
=- -
-+
- - -
- -
=-
-+
-
- -
=-
+ - -
=-
-
=-
=
b b ]] ]]
]]
] ]]
]]
] ]]
] ]] ]
]]
]] ]
]] ]
]]
]b
l l gg gg
gg
g gg
gg
g gg
g gg g
gg
gg g
gg g
gg
gl
Answer S13.indd 847 7/11/09 2:47:47 PM
848 Maths In Focus Mathematics Extension 1 Preliminary Course
Test yourself 13
1. (a) 5040 (b) 720 2. (a) 114
(b) 2213
(c) 2217
3. (a) 24 (b) 12 4. (a) 720 (b) 120
5. (a) 65 780 (b) 25 200 (c) 252 6. 29%
7. 120 8. 2.4 1018# 9.
91
10. 142 506
11. 990 12. (a) 40 320 (b) 362 880 (c) 80 640 (d) 168
13. (a) 19 958 400 (b) 4 989 600 (c) 181 440 (d) 9 979 200 (e) 181 440
14. ! !
!nn k k
nk =
-b ]l g 15. (a) 151 200 (b) 881 280
16. 1.08 1017#
17. (a) 1 709 316 (b) 203 490 (c) 167 580
18. (a) 15 (b) 181 440 19. 37 015 056
20. (a) 1
(b) n
! !!
! !!
! !!
! !!
nn
nn
nn n n n
n
nn
n nn
0 0
01
01
0`
=-
=
=
=-
=
=
=
0c ]
c ]
c c
m g
m g
m m
Challenge exercise 13
1. (a) 60 (b) 72 (c) 30 2. (a) 360 (b) 60
3. ! !
!nk n k k
n=
-b ]l g
( ) ! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
!
! !
! !
! !
!
! !
!
! !!
nk
nk n k k
n
n k k
n
n k k
n
n k k
n
k n k k
k n
n k n k k
n k n
n k k
k n
n k k
n k n
n k k
k n n k n
n k k
n k n k
n k k
n n
n k kn
11
11 1 1
1
1
1
1
1
1
1
1
1
1
1
1 1
1 1
1
1
--
+-
=- - - -
-+
- -
-
=- -
-+
- -
-
=- -
-+
- - -
- -
=-
-+
-
- -
=-
- + - -
=-
- + -
=-
-
=-
b b ]]
]]
] ]]
]]
] ]]
] ]] ]
]]
]] ]
]] ] ]
]]
]]
]
l l gg
gg
g gg
gg
g gg
g gg g
gg
gg g
gg g g
gg
gg
g
5
5
?
?
nk
nk
nk
11
1` =
--
+-b b bl l l
4. (a) 1 !n -] g (b) !
!k
n k 1- +] g 5. (a) 90 720 (b) 246
6. (a) 792 (b) 445
7. n
!!
! !! !
!
!!
!
Pn r
n
r C rn r r
n
n rn
P r C
r
nr
nr
nr`
=-
=-
=-
=
]]]
ggg
8. (a) 1 860 480 (b) 41
(c) 403
(d) 4021
9. (a) 94 109 400 (b) 7920 (c) 5 527 200 (d) 93 024 (e) 37 643 760 (f) 23 289 700
10. (a) 354
(b) 3517
Practice assessment task set 4
1. 21
2. 1 1 4P x x x x= - + +] ] ] ]g g g g 3. 3y x4=
4. (a) 362 880 (b) 4320 (c) 282 240 5. ,1 2-
6. ,19 10^ h 7. (a) 4- (b) −2 (c) 43
(d) 10
8. 2;x y2 2+ = circle centre ,0 0^ h radius 2
9. ;3060 161 3c c l
10. Distance from centre ,0 0^ h to line is
| |d
a b
ax by c
1040
4radius
line is tangent
2 2
1 1
`
=+
+ +
=
=
=
11. k 221
= -
12. x 74c= ( s+ in alternate segment)
( )
( )y 180 74 2
53 sum in isosceles'c c
c + D
= -
=
13. 120 14. ,x x2 21 2-
15. ( ) ( ) ( ) ( )( ) ( )
( ) ( ) ( ) ( )
P x x Q xP x x Q x x Q xP Q
P Q Q
22 2 2
2 2 2 20
2 2 2 2 2 2 2 20
= -
= - + -
= -
=
= - + -
=
2
2
2
2
l l
l l
] ] ]]]]
g g gggg
16. (a) 1 (b) 3 (c) ,101
0ab a b= - + =
17. 126 18. 7 19. 7.1 m 20. 131 38c l
Answer S13.indd 848 7/25/09 2:38:41 PM
849ANSWERS
21. (a) 1 3P x x x 2= - -] ] ]g g g (b) y
x31
-9
22.
23. P
x x x xP
2 55
2 2 11 232 is the remainder
2
`
- = -
+ - +
-
P 55 on division= -
]] ] ^]
gg g hg
24. (a) 0ad
abc acd bcd abd+ + + = - = (b) 1 (c) 1-
25.
( ) ( ) ( ) ( )( ) ( ) ( )
P x x Q xP Q
Q
P x x Q x x Q xP Q Q
Q Q
33 3 3 3
0 302 3 3
3 2 3 3 3 3 3 32 0 3 0 30
2
= -
= -
=
=
= - + -
= - + -
= +
=
2
2
2l l
l l
l
] ] ]] ] ]
]] ] ] ] ]
]
g g gg g g
gg g g g g
g
26. 1 884 960 27. Radius 3; 9x y2 2+ =
28. , ,a b c3 14 9= = - =
29. (a) 8.1 m (b) 35 46c l
30. (a) 1!
(b) ( ) ( )
( ) ( )
( ) ( ) ( ) ( )
P
P x x x x x x
P
1 1 1 1 50
6 1 5 1 2
1 6 1 1 1 1 5 1 1 2 10
2 3 2
2 2 2 2 3
2 2 2 2 3
$
$
= - +
=
= - + + -
= - + + -
=
l
l
^
^ ^^ ^
h
h hh h
31. Domain: all real x ; range: y 3$ -
32. )|ED(
,
ACB ECDABC CEDAC CD
ABC CDEby AAS
vertically opposite anglesalternate angles
given
AB|
`
+ ++ +
/D D
=
=
=
^^
hh
33. 46 m 2 34. 3 0x y+ - =
35. x x x12 36 62 2- + = -] g 36. 41 38c l
37. . , .y y2 5 6 5$ # -
38.
39. ,174
771
-d n 40. (a) x y9 16 0- + = (b) x y9 20 0+ + =
(c) ,Q 20 0= -^ h (d) 27 21c l
41. Domain: all real ;x 2!! range: all real y
42. (a) sin a b-^ h (b) 45cos2
1c= (c)
83 1
2+^ h
43. (a) 149.1 m (b) 46 48c l 44. 7.5,17.5X = ^ h 45. 3 46. , .x x1 1 61 2 47. x 150c=
48. (a) 8 129 0x y- + = (b) ,R 781
17641
= d n
49. t
t t t t
1
2 6 2 12
4 3 2
+
+ - + +2^ h
50. f x x x xf
3 7 5 33 3 3 7 3 5 3 3
81 63 15 30
3 2
3
= - - -
= - - -
= - - -
=
2
]] ] ] ]gg g g g
So x 3- is a factor of f x x x x3 7 5 33 2= - - -] g
51. , ,a b c1 3 1= = - = -
52. ,x y x y3 1 0 3 7 0- - = + - =
53. 2175 cm 3 ; 1045 cm 2
54. ,y y3 2 11 1 1- - - 55. 6556
56. (a) ,, ,x 60 120 240 300c c c c= (b) , ,x 0 90 360c c c=
(c) x 270c=
Answer S13.indd 849 7/11/09 2:47:51 PM
850 Maths In Focus Mathematics Extension 1 Preliminary Course
57. (a) 0
(b)
58. n90 1 135# #c ci = + - n] g 59. 8 8c l
60. . , .x y6 5 2 8= - = 61. y x4= -
62. (a) 4 (b) −2 (c) −3 (d) 121
(e) 22
63. 2 1 5P x x x2= - + +] ] ^g g h 64. 15 504
65. P x x x5 1= - - + 2] ] ]g g g 66. 63 67. (a)
68. (b) 69. (c) 70. (a), (b), (d)
71. (b) 72. (b) 73. (a) 74. (d)
75. (d)
Answer S13.indd 850 7/11/09 2:47:55 PM