maths resources Integrals?

Question

Are there any good tutorial websites or resourses to learn how to solve integrals.

I find it difficult to solve integrals such as:

(x^3)(cos3x)

thanks

Answer 1

use integral by parts.
search google
try to solve integral questions at www.pekiyi.150m.com/uys.html

Answer 2

I'm soryy. I don't know of any websites which teach integration. But you should use integration by parts.