Suppose sin of alpha = 3/5, pi/2<alpha<pi, and cos of beta = the square root of 3/2<beta<2pi.

Question

Evaluate the following: a) sin(alpha-beta) b) cos (alpha+beta)

Answer 1

First, find the values of alpha and beta using the inverse sin and cos functions. Then use the difference of angles formula for sin and the sum of angles formula for cos. Give it a shot, and come back with your attempt at solving it if you're still confused.