What is the derivative of f(x)=(cos^-1(x))/xf(x)=cos1(x)x ?

1 Answer
Jul 28, 2014

f'(x)=-1/(xsqrt(1-x^2))-(cos^-1x)/x^2

Using Quotient Rule, which is

y=f(x)/g(x), then y'=(f'(x)g(x)−f(x)g'(x))/(g(x))^2

Applying this for given problem, which is f(x)=(cos^-1x)/x

f'(x)=((cos^-1x)'(x)-(cos^-1x)(x)')/x^2

f'(x)=(-1/sqrt(1-x^2)*x-cos^-1x)/x^2

f'(x)=-1/(xsqrt(1-x^2))-(cos^-1x)/x^2, where -1<x<1