Answer
$$θ=\frac{\pi }{6}$$
Work Step by Step
Solving the equation using inverse trigonometric functions, we find:
$$-2\sin \left(θ\right)=-1,\:0\le \:θ\le \frac{\pi }{2} \\ \sin \left(θ\right)=\frac{1}{2} \\ θ=\frac{\pi }{6}+2\pi n,\:θ=\frac{5\pi }{6}+2\pi n \\ θ=\frac{\pi }{6}$$