Using principal value, calculate the following : $$\sin^{-1} \bigg( \sin \large\frac{3\pi}{5} \bigg).$$

Ans:

$Sin^{-1}sin(\pi-\frac{2\pi}{5})=Sin^{-1}sin\frac{2\pi}{5}=\frac{2\pi}{5}$
answered Feb 16, 2013