Answer
$\frac{\pi}{4},\frac{3\pi}{4},\frac{5\pi}{4},\frac{7\pi}{4}$
Work Step by Step
$2sin^2\theta-1=0$,
$sin\theta=\pm\frac{\sqrt 2}{2}$,
$\theta=\frac{\pi}{4},\frac{3\pi}{4},\frac{5\pi}{4},\frac{7\pi}{4}$ in $[0,2\pi)$.
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