Given that 2sin^2 theta + sin theta - 1 = 0, find the two values for sin theta.

2sin^2 θ + sin θ - 1 = 0

2sin^2 θ + 2sin θ - sin θ - 1 = 0

2sin θ (sin θ + 1) - 1 (sin θ + 1) = 0

(2sin θ - 1) (sin θ + 1) = 0

2sin θ - 1 = 0 or sin θ + 1 = 0

sin θ = 1/2 or sin θ = - 1

The two values of sin θ are 1/2 and - 1