Answer
$s = \{-\frac{3\pi}{4}, -\frac{\pi}{4}, \frac{\pi}{4}, \frac{3\pi}{4}\}$
Work Step by Step
$sin^2~s = \frac{1}{2}$
$sin~s = \pm \frac{1}{\sqrt{2}}$
Since $\frac{y}{r} = \pm \frac{1}{\sqrt{2}}$, the angle $s$ makes an angle of $\frac{\pi}{4}$ with the x-axis.
In the interval $[-\pi, \pi)$:
$s = \{-\pi+\frac{\pi}{4}, -\frac{\pi}{4}, \frac{\pi}{4}, \pi-\frac{\pi}{4}\}$
$s = \{-\frac{3\pi}{4}, -\frac{\pi}{4}, \frac{\pi}{4}, \frac{3\pi}{4}\}$
