(Solved): Use the trigonometric identity sinsin=21[cos()cos(+)] to compute the integral ...
Use the trigonometric identity sin?sin?=21?[cos(???)?cos(?+?)] to compute the integral ?0L?sinLn?x?sinLm?x?dx for integer n>0 and m>0. Be mindful of the case n=m.
![Use the trigonometric identity
\[
\sin \alpha \sin \beta=\frac{1}{2}[\cos (\alpha-\beta)-\cos (\alpha+\beta)]
\]
to compute t](https://media.cheggcdn.com/study/ebe/ebe4f8a5-d00a-48d4-8a4d-4be2e87a00f5/image)