The principal value of $cosec^{-1}\left(\frac{2}{\sqrt{3}}\right)$ is :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $\frac{\pi}{3}$
$θ=cosec^{-1}\left(\frac{2}{\sqrt{3}}\right)$
Now,
$cosec\,θ=\frac{1}{\sin θ}$
and,
$\frac{1}{\sin θ}=\frac{2}{\sqrt{3}}⇒\sin θ=\frac{\sqrt{3}}{2}$
Now,
$\sin θ=\frac{\sqrt{3}}{2}$
$⇒θ=\frac{\pi}{3}$