Integral of sin^4xcos^4xdx dx
The solution
Detail solution
-
Rewrite the integrand:
sin4(x)cos4(x)=(21−2cos(2x))2(2cos(2x)+21)2
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There are multiple ways to do this integral.
Method #1
-
Rewrite the integrand:
(21−2cos(2x))2(2cos(2x)+21)2=16cos4(2x)−8cos2(2x)+161
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos4(2x)dx=16∫cos4(2x)dx
-
Rewrite the integrand:
cos4(2x)=(2cos(4x)+21)2
-
There are multiple ways to do this integral.
Method #1
-
Rewrite the integrand:
(2cos(4x)+21)2=4cos2(4x)+2cos(4x)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(4x)dx=4∫cos2(4x)dx
-
Rewrite the integrand:
cos2(4x)=2cos(8x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(8x)dx=2∫cos(8x)dx
-
Let u=8x.
Then let du=8dx and substitute 8du:
∫8cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=8∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 8sin(u)
Now substitute u back in:
8sin(8x)
So, the result is: 16sin(8x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+16sin(8x)
So, the result is: 8x+64sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4x)dx=2∫cos(4x)dx
-
Let u=4x.
Then let du=4dx 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(4x)
So, the result is: 8sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫41dx=4x
The result is: 83x+8sin(4x)+64sin(8x)
Method #2
-
Rewrite the integrand:
(2cos(4x)+21)2=4cos2(4x)+2cos(4x)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(4x)dx=4∫cos2(4x)dx
-
Rewrite the integrand:
cos2(4x)=2cos(8x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(8x)dx=2∫cos(8x)dx
-
Let u=8x.
Then let du=8dx and substitute 8du:
∫8cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=8∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 8sin(u)
Now substitute u back in:
8sin(8x)
So, the result is: 16sin(8x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+16sin(8x)
So, the result is: 8x+64sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4x)dx=2∫cos(4x)dx
-
Let u=4x.
Then let du=4dx 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(4x)
So, the result is: 8sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫41dx=4x
The result is: 83x+8sin(4x)+64sin(8x)
So, the result is: 1283x+128sin(4x)+1024sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8cos2(2x))dx=−8∫cos2(2x)dx
-
Rewrite the integrand:
cos2(2x)=2cos(4x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4x)dx=2∫cos(4x)dx
-
Let u=4x.
Then let du=4dx 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(4x)
So, the result is: 8sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+8sin(4x)
So, the result is: −16x−64sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫161dx=16x
The result is: 1283x−128sin(4x)+1024sin(8x)
Method #2
-
Rewrite the integrand:
(21−2cos(2x))2(2cos(2x)+21)2=16cos4(2x)−8cos2(2x)+161
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫16cos4(2x)dx=16∫cos4(2x)dx
-
Rewrite the integrand:
cos4(2x)=(2cos(4x)+21)2
-
Rewrite the integrand:
(2cos(4x)+21)2=4cos2(4x)+2cos(4x)+41
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫4cos2(4x)dx=4∫cos2(4x)dx
-
Rewrite the integrand:
cos2(4x)=2cos(8x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(8x)dx=2∫cos(8x)dx
-
Let u=8x.
Then let du=8dx and substitute 8du:
∫8cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=8∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 8sin(u)
Now substitute u back in:
8sin(8x)
So, the result is: 16sin(8x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+16sin(8x)
So, the result is: 8x+64sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4x)dx=2∫cos(4x)dx
-
Let u=4x.
Then let du=4dx 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(4x)
So, the result is: 8sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫41dx=4x
The result is: 83x+8sin(4x)+64sin(8x)
So, the result is: 1283x+128sin(4x)+1024sin(8x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8cos2(2x))dx=−8∫cos2(2x)dx
-
Rewrite the integrand:
cos2(2x)=2cos(4x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(4x)dx=2∫cos(4x)dx
-
Let u=4x.
Then let du=4dx 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(4x)
So, the result is: 8sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+8sin(4x)
So, the result is: −16x−64sin(4x)
-
The integral of a constant is the constant times the variable of integration:
∫161dx=16x
The result is: 1283x−128sin(4x)+1024sin(8x)
-
Add the constant of integration:
1283x−128sin(4x)+1024sin(8x)+constant
The answer is:
1283x−128sin(4x)+1024sin(8x)+constant
The answer (Indefinite)
[src]
/
|
| 4 4 sin(4*x) sin(8*x) 3*x
| sin (x)*cos (x) dx = C - -------- + -------- + ---
| 128 1024 128
/
∫sin4(x)cos4(x)dx=C+1283x−128sin(4x)+1024sin(8x)
The graph
3
3 3*cos(2)*sin(2) sin (2)*cos(2)
--- - --------------- - --------------
128 256 128
−128sin3(2)cos(2)−2563sin(2)cos(2)+1283
=
3
3 3*cos(2)*sin(2) sin (2)*cos(2)
--- - --------------- - --------------
128 256 128
−128sin3(2)cos(2)−2563sin(2)cos(2)+1283
3/128 - 3*cos(2)*sin(2)/256 - sin(2)^3*cos(2)/128
Use the examples entering the upper and lower limits of integration.