Question

Find the values of θ, where 0° ≤ θ ≤ 360°, such that:

c) sin θ(2 cos θ -3) = 0

help pls 3

Answer 1

θ = 180° or 360°

Explanation:

sin θ(2 cos θ -3) = 0

either sin θ = 0 or 2 cos θ -3 = 0

since -1 ≤ cos θ ≤ 1, therefore 2 cos θ -3 never equals 0 (-2 ≤ 2 cos θ ≤ 2)

∴ sin θ = 0 0° ≤ θ ≤ 360 θ = 180° or 360°