Stuck on a step

use the exponential form for the trig functions and multiply through. you'll get a few easy integrals of the form
[tex]\int e^{(a+ib)x}dx[/tex]

 

If you don't know about the complex exponential, here's a technique using integration by parts (I'll let you tailor it to your specific example):
Suppose you are to find an anti-derivative (i.e, indefinite integral) of the function [tex]f(x)=e^{x}\sin(x)[/tex], that is, you are to find J, where J is given as:
[tex]J=\int{e}^{x}\sin(x)dx(1)[/tex]
The right-hand side can now be rewritten as:
[tex]\int{e}^{x}\sin(x)dx=e^{x}\sin(x)-\int{e}^{x}\cos(x)dx=e^{x}\sin(x)-e^{x}\cos(x)-\int{e}^{x}\sin(x)dx=e^{x}\sin(x)-e^{x}\cos(x)-J(2)[/tex]
where I have used integration by parts twice, along with (1).
Thus, we have:
[tex]J=e^{x}\sin(x)-e^{x}\cos(x)-J\to{J}=\frac{e^{x}\sin(x)-e^{x}\cos(x)}{2}[/tex]
(I've not bothered with the constant of integration; this should also be included in the final expression).

 

Sure; we've got the "abra-kadabra" formula, but it is only taught to 50 year old professor with proven gentle disposition because of the formula's potential for abuse.