# How to find the derivative of (cosec2x)?

$csc^{2}x =\frac{1}{sin^{2}x}$

Using the chain rule we get

$\frac{\mathrm{d} }{\mathrm{d} x}(csc^{2}x)=-\frac{2}{sin^{3}x}\frac{\mathrm{d} }{\mathrm{d} x}sin x=-\frac{2cos x}{sin^{3}x}=-2 cotxcsc^{3}x$