Some Exercises on Integral and Their Solutions
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Transcript of Some Exercises on Integral and Their Solutions
8/17/2019 Some Exercises on Integral and Their Solutions
http://slidepdf.com/reader/full/some-exercises-on-integral-and-their-solutions 1/25
1. dxx41 2∫ −
⇒ Misalkan
dααcos2
1dxαcos2
1
dα
dxαsin2
1x =⇒=⇒=
( ) ( )x2sinarcααsinx2αsin2
1x =⇒=⇒=
dααcos2
1αsin1dααcos
2
1αsin
4
141dxx41
222 ∫ ∫ ∫ −=
−=−
∫ ∫ == dααcos2
1dααcos
2
1αcos
2
α
2x1
2x41−
8/17/2019 Some Exercises on Integral and Their Solutions
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⇒ Ingat trigonometri
αcos2
1
4
1
α2cos4
1
4
1
αcos2
1
α2cos4
1
1αcos2α2cos
222
=+⇒−=⇒−=
Maka
C4
αα2sin
8
1dα
4
1α2cos
4
1dααcos
2
1 2 ++=
+= ∫ ∫
⇒ Ingat trigonometri
αcosαsin2α2sin =
( ) ( )( ) Cx2sinarc
4
1x41
2
xC
4
ααcosαsin
4
1C
4
αα2sin
8
1 2 ++−=++=++
Maka
8/17/2019 Some Exercises on Integral and Their Solutions
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( ) ( )( ) Cx2sinarc4
1x41
2
xdxx41
22 ++−=−∫
2. dx
4xx
1
22∫
−
⇒ Misalkan
dx
4a
daa
a
4a
dx
da
4x
x
dx
da4xa
2
2
2
2 =
+
⇒+
=⇒
−
=⇒−=
( ) ( )∫ ∫ ∫
+=
+
+=
−2
3
22222
4a
da
4a
daa
a4a
1dx
4xx
1
⇒ Misalkan
dααcos
2da
αcos
2
dα
daαtan2a
22
=⇒=⇒=
4αtan44aαtan2a 22 +=+⇒=
8/17/2019 Some Exercises on Integral and Their Solutions
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Maka
( ) ( ) ( ) ( )( )
∫ ∫ ∫ ∫
=
+
=
+
=
+ 2
3
2
2
2
3
2
2
2
3
2
2
2
3
2
αcos
18
dα
αcos
2
1αtan8
dα
αcos
2
4αtan4
dα
αcos
2
4a
da
( )
( ) ( ) C
4a
a
4
1C
4
αsin
4
dααcos
αcos
18
dααcos
2
2
2
3
2
2
++
=+=
=
= ∫ ∫
α
a
2
4a2 +
8/17/2019 Some Exercises on Integral and Their Solutions
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( )C
4a
a
4
1
4a
da
2
2
3
2
++
=
+∫
Jadi integralnya menhasilkan :
Cx
4x
4
1dx
4xx
1 2
22+
−=
−∫
3. dxx
1x2
∫
+
⇒ Misalkan
dx
1a
daa
a
1a
dx
da
1x
x
dx
da1xa
2
2
2
2 =−
⇒−
=⇒+
=⇒+=
8/17/2019 Some Exercises on Integral and Their Solutions
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Maka
da1a
ada
1a
daa
1a
adx
x
1x
2
2
22
2
∫ ∫ ∫
−=
−
−=
+
⇒ Lakkan !roses !em"agian
1a
11
1a
a
22 −+=
−
Maka
da1a
1ada
1a
1dada
1a
11da
1a
a
2222
2
∫ ∫ ∫ ∫ ∫
−+=
−+=
−+=
−
8/17/2019 Some Exercises on Integral and Their Solutions
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⇒ Lakkan !roses al#a"ar
1a
$
1a
%
1a
1
2 ++−=−
( ) ( )
1a
1a$1a%
1a
1
22 −−++
=−
( )
1a
$%a$%
1a
1x&
22 −−++
=−+
Maka' agar ras kiri sama dengan ras kanan'
1$%
&$%
=−=+
dengan mengrangkan !ersamaan !ertama dan keda' kita !eroleh
8/17/2019 Some Exercises on Integral and Their Solutions
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2
1$ −=
("stitsi hasil ini ke dalam salah sat !ersamaan di atas' kita !eroleh
&2
1%&$% =
−+⇒=+
2
1% =
Jadi' kita !eroleh !enyelesaian ntk sistem !ersamaan linear di atas' yait
2
1% =
2
1$ −=
(ehingga
8/17/2019 Some Exercises on Integral and Their Solutions
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da1a
2
1
1a
2
1
ada1a
1ada
1a
a
22
2
∫ ∫ ∫
+
−+
−+=
−+=
−
( ) ( ) C1aln2
1
1aln2
1
ada1a
a
2
2
++−−+=
−∫
Maka integral
( ) ( ) C11xln2
111xln
2
11xdx
x
1x 222
2
+++−−+++=
+∫
4. dxxx21
1
42∫
++
⇒ )lis
8/17/2019 Some Exercises on Integral and Their Solutions
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( ) 2242
1x
1
xx21
1
+=
++
( ) dx
1x
1
22
∫
+
⇒ Misalkan
dααcos
1dx
αcos
1
dα
dxαtanx
22
=⇒=⇒=
( ) ( )αcos
11αtan1xαtanx4
2222 =+=+⇒=
α
x
1
1x2 +
8/17/2019 Some Exercises on Integral and Their Solutions
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( ) ( )∫ ∫ ∫ =
=
+dααcosdα
αcos
1
αcos
1
1dx
1x
1 2
2
4
22
⇒ Ingat trigonometri
αcos2
1α2cos
2
1
2
1αcosα2cos
2
11αcos2α2cos
222 =+⇒−=⇒−=
( ) Cα2sin
4
1
2
αdα
2
1α2cos
2
1dx
1x
1
22
++=
+=
+ ∫ ∫
maka integral di atas menghasilkan
( ) C
1x
x
2
1xtanarc
2
1dx
1x
1
222
+
++=
+∫
8/17/2019 Some Exercises on Integral and Their Solutions
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*. ( dx3xx∫ +
⇒ Misalkan
dxda1dx
da3xa =⇒=⇒+=
Maka
( ) ( )( ) Ca2a*
2daa3adaa3adx3xx 2
3
2
*
2
1
2
3
+−=
−=−=+ ∫ ∫ ∫
( ) ( ) ( ) C3x23x*2dx3xx 2
3
2
*
++−+=+∫
8/17/2019 Some Exercises on Integral and Their Solutions
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+. dx4x
x3x2
∫
++
⇒ )liskan
4x
2&2&1+1+x*x8x
4x
x3x 22
+−+−+−+
=+
+
4x
4
4x
&2x*
4x
1+x8x2
++
++
−+++
=
( ) ( )
4x
4
4x
4x*
4x
4x 2
++++
−++
=
( ) ( )∫ ∫
++
++
−+
+=
++
dx4x
4
4x
4x*
4x
4xdx
4x
x3x 22
( ) ( )∫ ∫ ∫ ∫ +
+++
−+
+=
++
dx4x
14dx
4x
4x*dx
4x
4xdx
4x
x3x 22
( ) ( )∫ ∫ ∫ ∫ −+++−+=
++
dx4x4dx4x*dx4xdx4x
x3x2
1
2
32
8/17/2019 Some Exercises on Integral and Their Solutions
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( ) ( ) ( ) ( ) ( )∫ ∫ ∫ ∫ +++++−++=
++ −
4xd4x44xd4x*4xd4xdx4x
x3x2
1
2
32
( ) ( ) ( ) C4x84x3
1&4x
*
2dx
4x
x3x2
1
2
3
2
*2
++++−+=
++∫
,. dx1x
x4
∫
−
⇒ )liskan
1x
11xxx
1x
x 23
4
−++++=
−
Maka
( ) ∫ ∫ ∫ ∫
−++++=
−++++=
−
dx1x
1dx1xxxdx
1x
11xxxdx
1x
x 23234
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( ) C1xlnxx2
1x
3
1x
4
1dx
1x
x 234
4
+−++++=
−∫
8. ( ) ( ) dx
1x12x
1x*
∫
−+
+
⇒ )liskan
( ) ( ) ( ) ( )1x
$
12x
%
1x12x
1x*
−
+
+
=
−+
+
( ) ( )
( ) ( )
( ) ( )1x12x
12x$1x%
1x12x
1x*
−+++−
=−+
+
( ) ( )
( )
( ) ( )1x12x
$%x$2%
1x12x
1x*
−++−+
=−+
+
Maka' agar ras kiri sama dengan ras kanan'
8/17/2019 Some Exercises on Integral and Their Solutions
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1$%
*$2%
=+−
=+
-ita !eroleh sistem !ersamaan linear' dengan da !ersamaan linear dan da aria"el' % dan $' yang
hars dicari.
1$%
*$2%
=+−=+
dengan men#mlahkan !ersamaan !ertama dan keda' kita !eroleh
2$ =
("stitsi hasil ini ke dalam salah sat !ersamaan di atas' kita !eroleh
1% =
8/17/2019 Some Exercises on Integral and Their Solutions
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Jadi' kita !eroleh !enyelesaian ntk sistem !ersamaan linear di atas' yait
1% =
2$ =
Maka integral di atas menghasilkan
( ) ( ) ( ) ( ) ( ) ( ) C1xln212xln
21dx
1x2
12x1dx
1x12x1x* +−++=
−++=
−+ + ∫ ∫
/. ∫
++
1
&
2 dx
x2x31
1
⇒ )lis
8/17/2019 Some Exercises on Integral and Their Solutions
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( ) ( )1x12x
1
x2x31
1
2 ++=
++
⇒ )liskan
( ) ( ) ( ) ( )1x
$
12x
%
1x12x
1
++
+=
++
( ) ( )( ) ( )
( ) ( )1x12x
12x$1x%
1x12x
1
+++++=
++
( ) ( )
( )
( ) ( )1x12x
$%x$2%
1x12x
1x&
+++++=
+++
Maka' agar ras kiri sama dengan ras kanan'
8/17/2019 Some Exercises on Integral and Their Solutions
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1$%
&$2%
=+=+
-ita !eroleh sistem !ersamaan linear' dengan da !ersamaan linear dan da aria"el' % dan $' yanghars dicari.
1$%
&$2%
=+=+
dengan mengrangkan !ersamaan !ertama dan keda' kita !eroleh
1$ −=
("stitsi hasil ini ke dalam salah sat !ersamaan di atas' kita !eroleh
2% =
8/17/2019 Some Exercises on Integral and Their Solutions
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Jadi' kita !eroleh !enyelesaian ntk sistem !ersamaan linear di atas' yait
2% =
1$ −=
Maka integral di atas menghasilkan
( ) ( ) ( ) ( )[ ]1
&
1
&
2 1xln12xlndx1x
1
12x
2dx
x2x31
1+−+=
+
−+
=
++ ∫ ∫
( ) ( )[ ] ( ) ( )[ ]
=−=+−+=
++∫
2
3ln2ln3ln1xln12xlndx
x2x31
1 1
&
1
&
2
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1&. ∫
−−−4
3
23
23
dxx2x
4x2x
⇒ )lis
( )2xx
41
x2x
4x2x
223
23
−−=
−−−
( ) ( )
( )∫ ∫ ∫ ∫
−−=
−−=
−
−− 4
32
4
3
4
32
4
323
23
dx
2xx
14dx1dx
2xx
41dx
x2x
4x2x
( ) ( )∫ ∫ ∫
−
−=
−
−=
−
−− 4
3
2
4
3
2
4
3
4
3
23
23
dx2xx
141dx
2xx
14xdx
x2x
4x2x
⇒ )liskan
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( ) ( )2x
C
x
$x%
2xx
1
22 −+
+=
−
( )
( ) ( )
( )2xx
xC2x$x%
2xx
1
2
2
2 −+−+
=−
( )
( ) ( )
( )2xx
$2x$%2xC%
2xx
1x&x&
2
2
2
2
−−+−++
=−
++
Maka' agar ras kiri sama dengan ras kanan'
1C&$2%&
&C&$%2
&C$&%
=+−
=++−=++
-ita !eroleh !enyelesaian ntk sistem !ersamaan linear di atas' yait
8/17/2019 Some Exercises on Integral and Their Solutions
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4
1% −=
2
1$ −=
4
1C =
Maka integral di atas menghasilkan
( )∫ ∫
−
−+
−−−=
−
−− 4
3
2
4
3
23
23
dx2x
41
x
21x
41
41dx
x2x
4x2x
( )∫ ∫ ∫
−
+
++=
−−− 4
3
4
3
2
4
3
23
23
dx2x
1dx
x
2x1dx
x2x
4x2x
+=
−−−
∫ 3
8ln
+
,dx
x2x
4x2x4
3
23
23
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