Question 3 (9 points) when computing certain trigonometric integrals via integration by parts, one sometimes bumps up against the wall of having to integrate a power of a trig function, e. g. sinn x = (sin x) n . in this exercise, you will verify the reduction formula for sine: if n ≥ 2 is an integer, z (sin x) n dx = − 1 n cos x(sin x) n−1 + n − 1 n z (sin x) n−2 dx. the name "reduction formula" comes from the fact that repeated applications will ultimately reduce the computation to r sin x dx (when n is odd) or r 1 dx (when n is even). (a) (3 points) apply the integration by parts formula to r (sin x) n dx by splitting off a sine factor and choosing dv = sin x dx