Answer:
θ = 0°
θ = 30°
θ = 150°
θ = 180°
Step-by-step explanation:
2sin² θ = sin θ
Then
2sin² θ - sin θ = 0
Then
sin θ (2sin θ - 1) = 0
Then
sin θ = 0 or 2sin θ - 1 = 0
Then
sin θ = 0 or sin θ = 1/2
…………………………………………
We have sin θ = 0 and - 270° ≤ θ ≤180°
Then
θ = 0 or θ = π = 180°
On the other hand,
sin θ = 1/2 and - 270° ≤ θ ≤180°
Then
θ = π÷6 or θ = 5π÷6
π÷6 = 30° and 5π÷6 = 150°
