Answer
a) Need to caculate the value of inverse trigonometric funtion $cosec$.
$csc^{-1}\sqrt 2=\frac{\pi}{4}$
b) Need to caculate the value of inverse trigonometric funtion $cosec$.
$csc^{-1}(-\frac{2}{\sqrt 3})=(-\frac{\pi}{3})$
c) Need to caculate the value of inverse trigonometric funtion $cos$.
$csc^{-1}(2)=\frac{\pi}{6}$
Work Step by Step
a) Need to caculate the value of inverse trigonometric funtion $cosec$.
$csc^{-1}\sqrt 2=\frac{\pi}{4}$
b) Need to caculate the value of inverse trigonometric funtion $cosec$.
$csc^{-1}(-\frac{2}{\sqrt 3})=(-\frac{\pi}{3})$
c) Need to caculate the value of inverse trigonometric funtion $cos$.
$csc^{-1}(2)=\frac{\pi}{6}$