(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I've come across integrals of exponential and trig functions and I have no idea how to do them. Integration by parts doesn't really work because they just derive into either e or another trig function.

One of them is [itex]\int[/itex]sin(a)*sin(b - a)da

Another is [itex]\int[/itex]e(a)*sin(a)da

2. Relevant equations

sin(x + y) =sinx(cosy) + siny(cosx)

cos(x + y) = cosx(cosy) - sinx(siny)

sin^2(x) = (1 - cos2x)/2

3. The attempt at a solution

I've tried to use the trig identity for sin(b-a), but that just gives an extremely long sin and cos statement that doesn't help. the one with e is even more confusing. How am I supposed to manually solve them?

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# Finding integrals of the product of trig functions

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