1. The problem statement, all variables and given/known data sin(4x) = 8cos3(x)sin(x)-4sin(x)cos(x) 2. Relevant equations All trigonometric identities 3. The attempt at a solution I can simplify the right side using the double angle identity to: sin(4x) = 4sin(2x)cos2(x)-2sin(2x) However, now I'm not sure what to do. Did I take a step in the wrong direction?