1 / | | 3 | x *cos(x) dx | / 0
Use integration by parts:
Let and let .
Then .
To find :
The integral of cosine is sine:
Now evaluate the sub-integral.
Use integration by parts:
Let and let .
Then .
To find :
The integral of sine is negative cosine:
Now evaluate the sub-integral.
Use integration by parts:
Let and let .
Then .
To find :
The integral of cosine is sine:
Now evaluate the sub-integral.
The integral of a constant times a function is the constant times the integral of the function:
The integral of sine is negative cosine:
So, the result is:
Add the constant of integration:
The answer is:
/ | | 3 3 2 | x *cos(x) dx = C - 6*cos(x) + x *sin(x) - 6*x*sin(x) + 3*x *cos(x) | /
6 - 5*sin(1) - 3*cos(1)
=
6 - 5*sin(1) - 3*cos(1)
Use the examples entering the upper and lower limits of integration.