$\displaystyle \int sin(x)cos(nx)dx$ where n is a positive entire Thank's.
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$\displaystyle \displaystyle sin(A)cos(B)=\frac{sin(A-B) + sin(A+B)}{2}$
Use $\displaystyle 2\sin mx\cos nx=\sin (m+n)x+\sin (m-n)x$ . Edited: Sorry, I didn't see General's post.
You could also integrate by parts twice and solve for the original integral.
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