use the identity , then take as a factor sinx
second one move the left side to the right side then take as a factor tan^2 x same strategy above
2 similar problems that are really challenging for me.
1) solve [0,2pi) sin 2x-sinx = 0
2) solve [0,2pi) tan^2x sinx= tan^2x
Also how do i rewrite cos^3 x so that it does not contain power greater than 1? I don't think i can use double angle identity since it has power of 3.. not multiples of 2