# How do you find the value for sin^ -1[cos( π/4)]?

To find the value, cos$\frac{\pi}{4}$ needs to converted to sine. In this case it is simple, as cos$\frac{\pi}{4}$ equals sin$\frac{\pi}{4}$, hence ${\sin}^{-} 1 \cos \left(\frac{\pi}{4}\right) = {\sin}^{-} 1 \sin \left(\frac{\pi}{4}\right) = \frac{\pi}{4}$