If a function is invertible, its inverse can also be differentiated: the derivative of the inverse is the reciprocal of the derivative, evaluated at the corresponding point.

Property — Derivative of the inverse function

If ff is a bijection and differentiable with f(x)0f'(x)\ne 0, the derivative of the inverse is: (f1)(y)=1f(f1(y)).(f^{-1})'(y) = \frac{1}{f'(f^{-1}(y))}. In Leibniz notation: dxdy=1dy/dx\dfrac{dx}{dy} = \dfrac{1}{dy/dx} — again, “like a fraction”.

Topics: Derivatives
Concepts: Derivative · Inverse function · Leibniz notation
Skills: Differentiating