1. The problem statement, all variables and given/known data Derive the following: y = (cosxsin2x)-2 2. The attempt at a solution Basically I saw this as a power rule with two products in the middle. So y = -2 (cos2cos2x-sinxsin2x)-1 But the correct answer is completely different, it's: 4(3sin2x - 1) all over cos2xsin32x Could someone please go through the steps to get to the correct solution? Thanks in advance!