− cot ( x ) csc ( x ) + csc 2 ( x )
[tex]\bf y=csc(x)-cot(x)\implies \cfrac{dy}{dx}=[-csc(x)cot(x)]~~-~~[-csc^2(x)] \\\\\\ \cfrac{dy}{dx}=csc^2(x)-csc(x)cot(x)[/tex]