# What is arcsin(sin 2pi/3)?

$\frac{\pi}{3}$
In sin x, x is multi-valued. The only value in the range $\left[- \frac{\pi}{2} , + \frac{\pi}{2}\right]$ Is defined as arcsin(sin x). Here, use sin $\left(\pi - x\right)$ = sin x to attain that value..