Web viewIf . θ is a multiple of π 2 the coordinate of the points on a unit circle involve 0...
Transcript of Web viewIf . θ is a multiple of π 2 the coordinate of the points on a unit circle involve 0...
0 30∨π6
45∨π4
60∨π3
90∨π2
cosθ 1 √32
1√2
12 0
sin θ 0 12
1√2
√32
1
If θ is a multiple of π2 the coordinate of the points on a unit circle involve 0 and ±1.
If θ is a multiple of π4 (but not a multiple of π2), the coordinates involve ± 1
√2 . If θ is a multiple of π6 (but not a multiple of π2), the
coordinate involve ± 12 and ± √3
2 .
y=A sin B ( x−C )+D
A = amplitudeB = PeriodC = Horizontal translation (by +C)D = Vertical translation
y=A sin B ( x+C )+D
A = amplitudeB = PeriodC = Horizontal translation (by -C)
D = Vertical translation
2πB = Period
A=max−¿min2
¿
D=max+min2
Area of an equilateral triangle –A=√3
4a2
Where ‘a’ is the side of the equilateral triangle.
Three identities in trigonometry – sin2 x+cos2 x=1 tan2 x+1=sec2 x 1+cot2 x=csc2 x
Where –- sec x= 1
cos x
- csc x= 1sin x
- cot x= 1tan x
Compound angle formulae –
sin(A + B) = sinAcosB + cosAsinB
sin(A - B) = sinAcosB - cosAsinB
cos(A + B) = cosAcosB - sinAsinBcos(A - B) = cosAcosB + sinAsinB
tan (A + B) = tanA + tanB 1 - tanAtanBtan (A - B) = tanA - tanB 1 + tanAtanB
Double angle formulae –
sin2A = 2sinAcosA
cos2A = cos2A - sin2A- cos2A = 1 - 2sin2A- cos2A = 2cos2A - 1
tan2A = 2tanA 1 - tan2A
Derivative functions –
d ¿¿
d ¿¿
d ¿¿
d ¿¿
d ¿¿
d ¿¿
Differential Calculus –
f ' ( x ) : lim h→0Slope→ f ( x+h )−f ( x )h
f ' ( x ) : lim x→aSlope→ f (x )−f (a )x−a
Slopeof tangent= −1Slope of normal
i .e. slope of tangent to a point is the negative reciprocal of the slope of the normal to that point on the curve.
-(equation of the curve)+(equation of the tangent)=0 If f ( x )=¿¿; f ' ( x )=n (a×b ) ¿¿
Where (a×b) is the derivative of the the highest degree of polynomial.
If f(x)=xn , then f ’(x) = nxn-1
If f(x)= cu(x) (i.e. c times u(x)), then f ’(x) = c u’(x)
If f(x) = u(x)+v(x), then f ’(x) = u’(x)+v’(x)
Chain rule - dydx=dydu
× dudx
Product rule – if f(x)=u(x)v(x)Then f ' x=u' ( x ) v ( x )+v ' ( x )u ( x )
Quotient rule – if, Q(x)= v (x )u(x)
Q’(x)=u' ( x ) v ( x )−u (x ) v ' ( x)(v (x ))2
i.e. if y=u/vdydx
=u 'v−v 'uv2
Complex numbers – |z*|=|z| |z|2 = z z* |z1z2| = |z1||z2| |z1/z2|=|z1|/|z2| (provided z2≠0) |z1z2z3z4…zn|=|z1||z2||z3||z4|…|zn| |zn| = |z|n
If z = |z|cis θ then z* = ¿ z∨cis (−θ)
|z|cisθ=¿z∨eiθ
(Polar Form) (Euler Form)
cis A × cis B = cis (A+B)
cis(A)cis(B) = cis (A-B)
cis (θ+2kπ ¿ = cis (θ ¿
Arg(zw) = Arg(z) + Arg(w)
Arg(z/w) = Arg(z) – Arg(w)
Arg(zn) = n Arg(z)
(|z| cis θ)n = |z|ncis nθ
z = a± ib
Quadratic equation representing ‘z’ –x2−¿
where, sum = a+ ib+a−ib (2a)& product = (a+ ib)(a−ib) (a2+b2)
(z*)*= z (zn)* = (z*)n
for n = 1,2 & 3
(z1+z2+z3+z4…+zn)* = (z1)*+(z2)*+(z3)*+(z4)*…+(zn)*
P(x )ax+b
=Q ( x )+ R (x)ax+b
where – Q(x) – quotient R(x) – remainder ax+b – divisor
When P(x) is divided by a factor x-k until a constant remainder ‘R’ is obtained – P(k) = R
P(x) = Q(x)(x-k)+RP(k)= Q(k)(k-k)+R as k-k=0P(k)= R
If ‘k’ is a zero of P(x), then (x-k) is a factor of P(x)
Counting and binomial expansion – t r+ 1=( Cr
n ) xn−rar
where, t r+ 1 is the (r+1)th term of the polynomial – (x+a)n
nCr=n!
r! (n−r )!
Quadratic functions and equations –
Discriminant (∆) = b2-4ac(ax2+bx+c)if ∆>0 – two distinct real rootsif ∆<0 – no real rootsif ∆=0 – single real repeated rootif ∆≥0 – two real roots
If ∆>0, the graph cuts x-axis twice ∆<0, does not touch the x-axis
∆=0, the graph touches the x-axis once
If ax2+bx+c has two roots – α∧β
Then – α+β=−b
a
andα× β= c
a
f(x) = ax2+bx+c, if a¿0 and ∆<0the graph is a negative parabola and if a¿0 and ∆<0 the graph is a positive parabola.
Logarithm –
(no negative numbers in logarithmic equations) log aa
n=n
log cA +logcB=logc ¿¿¿
log cA−logcB=logc (AB ¿)¿
n log cA=logc (An)
ln e x=x∧e ln x=x
(examples – ln1 = lne0 = 0lne = ln e1 = 1)
ax=e x ln a
log b A=logc Alogcb
Exponentials –
Laws of Indices –1. am×an = am+n
2. am
an=am−n , where a ≠ 0
3. ( ab)n
=an
bn, where b≠0
4. (am)n = amn
5. (ab)n = anbn
6. a0 = 1, where a ≠ 07. a−n= 1
an , where a ≠ 08. a
1n=n√a
9. amn=
n√am
10. If ax = ay, then x = y
Matrices –
We can add or subtract two matrices only if they are of the same order i.e. both are 2× 2, 3 × 3, etc.
¿
Matrix – A × BOrder of matrix A - n×mOrder of matrix B - u×vOrder of matrix AB = n×vProvided m=u, if m≠u – AB cannot be multiplied.
Matrix A = a bc d
Then |A| (determinant of matrix A) = ad – bc
If |A| = 0, the matrix is singular and has no inverse.
Matrix A = a bc d , then
Matrix A-1 = 1
¿ A∨¿×( d −b−c a )¿
Equations – ax+ by = c dx+ ey = fcan be written as –
(for 2 equations)Last row – all zero’s – infinite solutions Two zero – no solutionsOne zero or no zero – unique solutions
(for 3 equations)All zero’s – infinite3 zero’s (last value) – no solution
one zero, two zero or no zero – unique solutions
Matrices – A & B(AB)-1 = B-1A-1
Sequences and series –
Arithmetic sequence – un = u1+ (n-1)d
Sum of first ‘n’ terms of an arithmetic sequence –
n2(2u1+(n−1)d )
where, u1 – the first term d – the common difference n – the no. of terms
Arithmetic sequence – d = un+1-un
Geometric sequence – un= u1 × rn-1
Sum of ‘n’ terms in a geometric progression – u1(r
n−1)r−1 or u1(1−rn)
1−r
Sum of infinite Geometric progression –u1
1−r
Compound Interest –un+1=u1+r
n
where, u1 is the principal and r is the rate and ‘n’ is the time.
Superannuation –Amount at the end ¿ ai { (1+ i¿¿¿n−1 }
Amount at the beginning = ai (1+i){(1+i ¿¿¿n−1 }
Principal at beginning =ai(1+i){1− (1+i ¿¿¿−n }
Principal at end = ai (1+i){1− (1+i ¿¿¿−n }