Answer
$\dfrac {\cos x}{\left( \sin ^{2}\left( cscx\right) \right) \times \sin ^{2}x}=\csc^2(cscx)cscx\ cotx$
Work Step by Step
$\dfrac {d}{dx}\left( \cot \left( cscx\right) \right) =-\dfrac {1}{\sin ^{2}cscx}\times \dfrac {d}{dx}\left( cscx\right) =\dfrac {\cos x}{\left( \sin ^{2}\left( cscx\right) \right) \times \sin ^{2}x}=\csc^2(cscx)cscx\ cotx$
