## Precalculus (6th Edition)

$\displaystyle \frac{\pi}{8}$ , $\displaystyle \frac{5\pi}{6},\ \displaystyle \frac{5\pi}{4}$
If $0 \leq x < 2\pi$ then $0 \displaystyle \leq \frac{x}{2} < \pi,$ and $x=2\displaystyle \cdot\frac{x}{2}$ so the corresponding values of x are $2\displaystyle \cdot\frac{\pi}{16}=\frac{\pi}{8}$ $2\displaystyle \cdot\frac{5\pi}{12}=\frac{5\pi}{6}$ $2\displaystyle \cdot\frac{5\pi}{8}=\frac{5\pi}{4}$