# How do you evaluate arcsin(1/sqrt(2))?

$\arcsin \left(\frac{1}{\sqrt{2}}\right) = \frac{\pi}{4} \left(= {45}^{\circ}\right)$
Assuming $\arcsin \left(x\right)$ is restricted to $\left[0 , \pi\right)$
the above diagram shows the only configuration for $\arcsin \left(\frac{1}{\sqrt{2}}\right)$