#### Answer

$\displaystyle \frac{\pi}{3},\ \pi,\ \displaystyle \frac{4\pi}{3}$

#### Work Step by Step

If $ 0 \leq x < 2\pi$ then
$ 0 \leq 2x < 4\pi$
and $x=\displaystyle \frac{2x}{2}$ so the corresponding values of x are
$\displaystyle \frac{\frac{2\pi}{3}}{2}=\frac{\pi}{3},$
$\displaystyle \frac{2\pi}{2}=\pi$
$\displaystyle \frac{\frac{8\pi}{3}}{2}=\frac{4\pi}{3}.$