# What does arcsin(cos ((-pi)/6))  equal?

$\frac{\pi}{3}$
$\cos \left(- \frac{\pi}{6}\right) = \cos \left(\frac{\pi}{6}\right) = \frac{\sqrt{3}}{2}$
$\arcsin \left(\frac{\sqrt{3}}{2}\right) = \frac{\pi}{3}$ Note range of $\arcsin \left(x\right)$ is $\left[- \frac{\pi}{2} , \frac{\pi}{2}\right]$