find soultuion in degree, use exact value

Question

1. cos2xcosx+sin2xsinx=-1/2

Answer 1

Do you mean cos (2x) or cos^2 x?
Do you mean sin (2x) or sin^2 x?
Use the idenitites for cos 2x and sin 2x in terms of sin x and cosx. You can end up with an equation that involves just cos x and sin x. If you take it that far, I can help you the rest of the way.