What is the derivative of this function y=csc^-1(x/2)?

1 Answer
Dec 23, 2016

The answer is =-2/(x^2sqrt(1-4/x^2))

Explanation:

We use

cos^2theta+sin^2theta=1

and (x^n)'=nx^(n-1)

y=csc^(-1)(x/2)

cscy=x/2

1/siny=x/2

siny=2/x

(siny)'=(2/x)'

cosydy/dx=-2/x^2

dy/dx=-2/(x^2cosy)

cosy=sqrt(1-sin^2y)=sqrt(1-4/x^2)

Therefore,

dy/dx=-2/(x^2sqrt(1-4/x^2))