Integral of 2sin6xsin2xdx dx
The solution
Detail solution
-
There are multiple ways to do this integral.
Method #1
-
Let u=2x.
Then let du=2dx and substitute du:
∫sin(u)sin(3u)du
-
Rewrite the integrand:
sin(3u)sin(u)=−4sin4(u)+3sin2(u)
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−4sin4(u))du=−4∫sin4(u)du
-
Rewrite the integrand:
sin4(u)=(21−2cos(2u))2
-
There are multiple ways to do this integral.
Method #1
-
Rewrite the integrand:
(21−2cos(2u))2=4cos2(2u)−2cos(2u)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(2u)du=4∫cos2(2u)du
-
Rewrite the integrand:
cos2(2u)=2cos(4u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4u)du=2∫cos(4u)du
-
Let u=4u.
Then let du=4du and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4u)
So, the result is: 8sin(4u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+8sin(4u)
So, the result is: 8u+32sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(2u))du=−2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: −4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫41du=4u
The result is: 83u−4sin(2u)+32sin(4u)
Method #2
-
Rewrite the integrand:
(21−2cos(2u))2=4cos2(2u)−2cos(2u)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(2u)du=4∫cos2(2u)du
-
Rewrite the integrand:
cos2(2u)=2cos(4u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4u)du=2∫cos(4u)du
-
Let u=4u.
Then let du=4du and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4u)
So, the result is: 8sin(4u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+8sin(4u)
So, the result is: 8u+32sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(2u))du=−2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: −4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫41du=4u
The result is: 83u−4sin(2u)+32sin(4u)
So, the result is: −23u+sin(2u)−8sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫3sin2(u)du=3∫sin2(u)du
-
Rewrite the integrand:
sin2(u)=21−2cos(2u)
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(2u))du=−2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: −4sin(2u)
The result is: 2u−4sin(2u)
So, the result is: 23u−43sin(2u)
The result is: 4sin(2u)−8sin(4u)
Now substitute u back in:
4sin(4x)−8sin(8x)
Method #2
-
The integral of a constant times a function is the constant times the integral of the function:
∫4sin(x)sin(6x)cos(x)dx=4∫sin(x)sin(6x)cos(x)dx
-
Rewrite the integrand:
sin(x)sin(6x)cos(x)=32sin6(x)cos2(x)−32sin4(x)cos2(x)+6sin2(x)cos2(x)
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫32sin6(x)cos2(x)dx=32∫sin6(x)cos2(x)dx
-
Rewrite the integrand:
sin6(x)cos2(x)=(21−2cos(2x))3(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(−32cos4(u)+16cos3(u)−16cos(u)+321)du
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−32cos4(u))du=−32∫cos4(u)du
-
Rewrite the integrand:
cos4(u)=(2cos(2u)+21)2
-
Rewrite the integrand:
(2cos(2u)+21)2=4cos2(2u)+2cos(2u)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(2u)du=4∫cos2(2u)du
-
Rewrite the integrand:
cos2(2u)=2cos(4u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4u)du=2∫cos(4u)du
-
Let u=4u.
Then let du=4du and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4u)
So, the result is: 8sin(4u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+8sin(4u)
So, the result is: 8u+32sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫41du=4u
The result is: 83u+4sin(2u)+32sin(4u)
So, the result is: −2563u−128sin(2u)−1024sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos3(u)du=16∫cos3(u)du
-
Rewrite the integrand:
cos3(u)=(1−sin2(u))cos(u)
-
Let u=sin(u).
Then let du=cos(u)du and substitute du:
∫(1−u2)du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: −3u3+u
Now substitute u back in:
−3sin3(u)+sin(u)
So, the result is: −48sin3(u)+16sin(u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos(u))du=−16∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: −16sin(u)
-
The integral of a constant is the constant times the variable of integration:
∫321du=32u
The result is: 2565u−128sin(2u)−1024sin(4u)−48sin3(u)
Now substitute u back in:
1285x−48sin3(2x)−128sin(4x)−1024sin(8x)
So, the result is: 45x−32sin3(2x)−4sin(4x)−32sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−32sin4(x)cos2(x))dx=−32∫sin4(x)cos2(x)dx
-
Rewrite the integrand:
sin4(x)cos2(x)=(21−2cos(2x))2(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(16cos3(u)−16cos2(u)−16cos(u)+161)du
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos3(u)du=16∫cos3(u)du
-
Rewrite the integrand:
cos3(u)=(1−sin2(u))cos(u)
-
Let u=sin(u).
Then let du=cos(u)du and substitute du:
∫(1−u2)du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: −3u3+u
Now substitute u back in:
−3sin3(u)+sin(u)
So, the result is: −48sin3(u)+16sin(u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos2(u))du=−16∫cos2(u)du
-
Rewrite the integrand:
cos2(u)=2cos(2u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+4sin(2u)
So, the result is: −32u−64sin(2u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos(u))du=−16∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: −16sin(u)
-
The integral of a constant is the constant times the variable of integration:
∫161du=16u
The result is: 32u−64sin(2u)−48sin3(u)
Now substitute u back in:
16x−48sin3(2x)−64sin(4x)
So, the result is: −2x+32sin3(2x)+2sin(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫6sin2(x)cos2(x)dx=6∫sin2(x)cos2(x)dx
-
Rewrite the integrand:
sin2(x)cos2(x)=(21−2cos(2x))(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(81−8cos2(u))du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫81du=8u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8cos2(u))du=−8∫cos2(u)du
-
Rewrite the integrand:
cos2(u)=2cos(2u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+4sin(2u)
So, the result is: −16u−32sin(2u)
The result is: 16u−32sin(2u)
Now substitute u back in:
8x−32sin(4x)
So, the result is: 43x−163sin(4x)
The result is: 16sin(4x)−32sin(8x)
So, the result is: 4sin(4x)−8sin(8x)
Method #3
-
Rewrite the integrand:
sin(2x)2sin(6x)=128sin6(x)cos2(x)−128sin4(x)cos2(x)+24sin2(x)cos2(x)
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫128sin6(x)cos2(x)dx=128∫sin6(x)cos2(x)dx
-
Rewrite the integrand:
sin6(x)cos2(x)=(21−2cos(2x))3(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(−32cos4(u)+16cos3(u)−16cos(u)+321)du
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−32cos4(u))du=−32∫cos4(u)du
-
Rewrite the integrand:
cos4(u)=(2cos(2u)+21)2
-
Rewrite the integrand:
(2cos(2u)+21)2=4cos2(2u)+2cos(2u)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(2u)du=4∫cos2(2u)du
-
Rewrite the integrand:
cos2(2u)=2cos(4u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4u)du=2∫cos(4u)du
-
Let u=4u.
Then let du=4du and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4u)
So, the result is: 8sin(4u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+8sin(4u)
So, the result is: 8u+32sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫41du=4u
The result is: 83u+4sin(2u)+32sin(4u)
So, the result is: −2563u−128sin(2u)−1024sin(4u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos3(u)du=16∫cos3(u)du
-
Rewrite the integrand:
cos3(u)=(1−sin2(u))cos(u)
-
Let u=sin(u).
Then let du=cos(u)du and substitute du:
∫(1−u2)du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: −3u3+u
Now substitute u back in:
−3sin3(u)+sin(u)
So, the result is: −48sin3(u)+16sin(u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos(u))du=−16∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: −16sin(u)
-
The integral of a constant is the constant times the variable of integration:
∫321du=32u
The result is: 2565u−128sin(2u)−1024sin(4u)−48sin3(u)
Now substitute u back in:
1285x−48sin3(2x)−128sin(4x)−1024sin(8x)
So, the result is: 5x−38sin3(2x)−sin(4x)−8sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−128sin4(x)cos2(x))dx=−128∫sin4(x)cos2(x)dx
-
Rewrite the integrand:
sin4(x)cos2(x)=(21−2cos(2x))2(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(16cos3(u)−16cos2(u)−16cos(u)+161)du
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos3(u)du=16∫cos3(u)du
-
Rewrite the integrand:
cos3(u)=(1−sin2(u))cos(u)
-
Let u=sin(u).
Then let du=cos(u)du and substitute du:
∫(1−u2)du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: −3u3+u
Now substitute u back in:
−3sin3(u)+sin(u)
So, the result is: −48sin3(u)+16sin(u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos2(u))du=−16∫cos2(u)du
-
Rewrite the integrand:
cos2(u)=2cos(2u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+4sin(2u)
So, the result is: −32u−64sin(2u)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−16cos(u))du=−16∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: −16sin(u)
-
The integral of a constant is the constant times the variable of integration:
∫161du=16u
The result is: 32u−64sin(2u)−48sin3(u)
Now substitute u back in:
16x−48sin3(2x)−64sin(4x)
So, the result is: −8x+38sin3(2x)+2sin(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫24sin2(x)cos2(x)dx=24∫sin2(x)cos2(x)dx
-
Rewrite the integrand:
sin2(x)cos2(x)=(21−2cos(2x))(2cos(2x)+21)
-
Let u=2x.
Then let du=2dx and substitute du:
∫(81−8cos2(u))du
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫81du=8u
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8cos2(u))du=−8∫cos2(u)du
-
Rewrite the integrand:
cos2(u)=2cos(2u)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2u)du=2∫cos(2u)du
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2u)
So, the result is: 4sin(2u)
-
The integral of a constant is the constant times the variable of integration:
∫21du=2u
The result is: 2u+4sin(2u)
So, the result is: −16u−32sin(2u)
The result is: 16u−32sin(2u)
Now substitute u back in:
8x−32sin(4x)
So, the result is: 3x−43sin(4x)
The result is: 4sin(4x)−8sin(8x)
-
Add the constant of integration:
4sin(4x)−8sin(8x)+constant
The answer is:
4sin(4x)−8sin(8x)+constant
The graph
3*cos(6)*sin(2) cos(2)*sin(6)
- --------------- + -------------
8 8
−83sin(2)cos(6)+8sin(6)cos(2)
=
3*cos(6)*sin(2) cos(2)*sin(6)
- --------------- + -------------
8 8
−83sin(2)cos(6)+8sin(6)cos(2)
-3*cos(6)*sin(2)/8 + cos(2)*sin(6)/8
Use the examples entering the upper and lower limits of integration.