Question

I skipped a step, can someone fix it?

I didn't show the factoring.

2 sin^2 x = 2 + cos x interval [0,pi]
2-2 cos^2x - 2 + cos x
cos x + 2 cos^2 x = 0
cos x = -1/2
cos x = 0

x = 2pi/3 , pi/2