What is the derivative of csc^2(x)?

1 Answer
Apr 13, 2018

d/dx[csc^2(x)]= -2cotxcsc^2x

Explanation:

csc^2(x)=1/sin^2(x)

d/dx[csc^2(x)]=d/dx[1/sin^2(x)]

d/dx[1/sin^2(x)]=d/dx[[sin(x)]^{-2}]

let u=sinx

d/dx[[sin(x)]^{-2}]=d/{du}[u^{-2}]d/dx[sinx]

d/{du}[u^{-2}]= -2u^{-3}

d/dx[sinx] = cosx

d/dx[[sin(x)]^{-2}]=-2u^{-3}cosx=-{2cosx}/{sin^3x}

cosx/sinx=cotx => -{2cosx}/{sin^3x}=-{2cotx}/{sin^2x}

1/sin^2x=csc^2x => -2cotxcsc^2x

d/dx[csc^2(x)]= -2cotxcsc^2x