Derivative of Nth Root

Theorem
Let $n \in \N_{>0}$.

Let $f: \R \to \R$ be the real function defined as $f \left({x}\right) = \sqrt [n] x$.

Then:
 * $f' \left({x}\right) = \dfrac 1 {n \left({\sqrt [n] x}\right)^{n-1} }$

everywhere that $f \left({x}\right) = \sqrt [n] x$ is defined.