Solve on the interval [0,2pi) 1-cos theta = (2 - sqrt 3)/2

Question

I dont quite remember how to solve this, if anyone could help.

Answer 1

let x=θ to make it easier

1-cosx=(2-√3)/2

cosx=1-(2-√3)/2

cosx=1-(1-[√3/2])

cosx=1-1+√3/2

cosx=√3/2

cos is √3/2 at ∏/6=30º and at 11∏/6=330º