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

(Headbang)

Thanks!!