Answer
$\dfrac{\pi}{3},\dfrac{2\pi}{3}$
Work Step by Step
Since $\sin(x)$ is the y-coordinate on the unit circle
As $\sin(x)=\dfrac{\sqrt{3}}{2}$, we search figure 22 for points where the y-coordinate is $\dfrac{\sqrt{3}}{2}$
The two angles on the unit circle where $\sin{x} = \dfrac{\sqrt{3}}{2}$ are $\dfrac{\pi}{3}$ and $\dfrac{2\pi}{3}$
$x= \dfrac{\pi}{3},\dfrac{2\pi}{3}$