Solve for , in the interval 0 180, the following equations. Give your answers

Solve for θ, in the interval 0 ≤ θ ≤ 180°, the following equations. Give your answers to 3 significant figures where they are not exact.

a. 4 (sin² θ − cos θ) = 3 − 2cos θ 

b. 2sin² θ = 3(1 − cos θ) 

c. 4cos² θ − 5sin θ − 5 = 0