I'm supposed to integrate pi ∫ (cos nx)(cosx)^2 dx 0 how do i integrate this?
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My first guess would be convert to and then it becomes a trivial integral plus a u-sub one.
First, use the half angle identity to get rid of the cos^2(x). Multiplying this with \cos{nx} will get you First one should be easy. For the second one, you can use either integration by parts or the product to sum identity:
I didn't see the (nx) term. Sorry. Obviously the above substitution is the one to go with now.
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