2. Ingat Aturan Rantai pada Turunan :
Jika kedua ruas diintegralkan, maka diperoleh
)('))(('))(( xgxgfxgf
dx
d
=
dxxgxgfdxxgf
dx
d
)('))(('))(( ∫∫ =
dxxgxgfCxgf )('))(('))(( ∫=+
dari definisi integral tak tentu
3. Misal u = g(x), maka du = g’(x)dx
Disubstitusi ke atas diperoleh
Cxgfdxxgxgf +=∫ ))(()('))(('
Cufduuf +=∫ )()('
4. 1. Mulai dengan fungsi yang diintegralkan
2. Kita misalkan u = g(x)
3. Hitung du
4. Substitusi u dan du
5. Integralkan
6. Ganti u dengan g(x)
5. Hitunglah
Jawab
Misalkan u = 3x + 5 , maka du = 3 dx , dx = 1/3 du
Substitusi ke fungsi di atas diperoleh
dxx )53sin( +∫
CxCuududxx ++−=+−==+ ∫∫ )53cos(cossin)53sin(
6. Hitunglah
Jawab
Misalkan u = -3x2
+ 5 , maka du = -6x dx atau
x dx = -1/6 du
dxxe x 53 2
9 +−
∫
CeCedue xuu
+−=+−=−= +−
∫
53 2
6
9
6
9
6
9
dxxe x 53 2
9 +−
∫
7. Hitunglah
Jawab
Misalkan u = cos x , maka du = -sin x dx atau
sin x dx = -du.
Sehingga
xdxtan∫
dx
x
x
xdx ∫∫ =
cos
sin
tan
CxCxCu
u
du
dx
x
x
xdx +=+−=+−=
−
== ∫∫∫ seclncoslnln
cos
sin
tan
9. Bentuk integral dapat
diselesaikan dengan metode Integral By Parts
(Integral sebagian – sebagian) , yaitu
dxxfxgxgxfdxxgxf ∫∫ −= )(')()()()(')(
dxxgxf∫ )()(
Atau lebih dikenal dengan rumus
duvuvdvu ∫∫ −=
10. Hitunglah
Jawab
Misalkan u = 3 – 5x , du = -5 dx.
dv = cos 4x , v = ¼ sin 4x dx
Maka
dxxx )4cos()53(∫ −
∫∫ −−−=− )5)(4sin()4sin()(53()4cos()53( 4
1
4
1
dxxxxdxxx
11. Hitunglah dxxx )ln()5( 3
∫ +
dxxe x
)cos(2
∫
dxxx )4cos(2
∫
a
b
c
Exercise
13. The method of Partial Fractions provides a way
to integrate all rational functions. Recall that a
rational function is a function of the form
where P and Q are polynomials.
1. The technique requires that the degree of the
numerator (pembilang) be less than the degree
of the denominator (penyebut)
If this is not the case then we first must divide
the numerator into the denominator.
dx
xQ
xP
∫ )(
)(
14. 2. We factor the denominator Q into powers of
distinct linear terms and powers of distinct
quadratic polynomials which do not have real
roots.
3. If r is a real root of order k of Q, then the partial
fraction expansion of P/Q contains a term of the
form
where A1, A2, ..., Ak are unknown constants.
k
k
rx
A
rx
A
rx
A
)()()( 2
21
−
++
−
+
−
15. 4. If Q has a quadratic factor ax2
+ bx + c which
corresponds to a complex root of order k, then the
partial fraction expansion of P/Q contains a term of
the form
where B1, B2, ..., Bk and C1, C2, ..., Ck are
unknown constants.
5. After determining the partial fraction expansion of
P/Q, we set P/Q equal to the sum of the terms of
the partial fraction expansion. (See Ex-2.Int.Frac)
k
kk
cbxax
CxB
cbxax
CxB
cbxax
CxB
)()( 222
22
2
11
++
+
++
++
+
+
++
+
16. 6. We then multiply both sides by Q to get some
expression which is equal to P.
7. Now, we use the property that two polynomials
are equal if and only if the corresponding
coefficients are equal.
(see ex3-int.Fractional)
8. We express the integral of P/Q as the sum of
the integrals of the terms of the partial fraction
expansion.
(see Ex4-Int.Fractional)
17. 9. Integrate linear factors:
rxAdx
rx
A
−=
−∫ ln
)(
1
1
111
)(
1)(
+−
−
+−
=
−∫
n
n
rx
n
A
dx
rx
A
for n > 1
18. 10. Integrate quadratic factors:
Some simple formulas:
++=
+
+
∫ a
x
A
C
ax
B
dx
ax
CBx
arctan)ln(
2
22
22
+
+
−
=
+
+
∫ a
x
a
C
axa
BaCx
dx
ax
CBx
arctan
2)(2)( 3222
2
222