Question

Find the principal value of $cose{c}^{-1}\left(\frac{2}{\sqrt{3}}\right)$

Answer 1

We've $cosec{60}^o=\frac{2}{\sqrt{3}}$.

So the principle value of $cose{c}^{-1}\left(\frac{2}{\sqrt{3}}\right)$ is ${60}^o$.