4*pi / | | (x + 1)*cos(x) | -------------- dx | 4 | / 2*pi
Integral(((x + 1)*cos(x))/4, (x, 2*pi, 4*pi))
The integral of a constant times a function is the constant times the integral of the function:
There are multiple ways to do this integral.
Rewrite the integrand:
Integrate term-by-term:
Use integration by parts:
Let and let .
Then .
To find :
The integral of cosine is sine:
Now evaluate the sub-integral.
The integral of sine is negative cosine:
The integral of cosine is sine:
The result is:
Use integration by parts:
Let and let .
Then .
To find :
The integral of cosine is sine:
Now evaluate the sub-integral.
The integral of sine is negative cosine:
So, the result is:
Now simplify:
Add the constant of integration:
The answer is:
/ | | (x + 1)*cos(x) cos(x) sin(x) x*sin(x) | -------------- dx = C + ------ + ------ + -------- | 4 4 4 4 | /
Use the examples entering the upper and lower limits of integration.