Question:
The value of $\sin ^{-1}\left(\cos \frac{33 \pi}{5}\right)$ isĀ ________________.
Solution:
$\sin ^{-1}\left(\cos \frac{33 \pi}{5}\right)$
$=\sin ^{-1}\left[\cos \left(6 \pi+\frac{3 \pi}{5}\right)\right]$
$=\sin ^{-1}\left(\cos \frac{3 \pi}{5}\right)$
$=\sin \left[\sin \left(\frac{\pi}{2}-\frac{3 \pi}{5}\right)\right]$
$=\sin \left[\sin \left(-\frac{\pi}{10}\right)\right]$
$=-\frac{\pi}{10}$
Thus, the value of $\sin ^{-1}\left(\cos \frac{33 \pi}{5}\right)$ is $-\frac{\pi}{10}$.
The value of $\sin ^{-1}\left(\cos \frac{33 \pi}{5}\right)$ is $-\frac{\pi}{10}$