# Steiner's Calculus Problem

## Theorem

Let $f: \R_{>0} \to \R$ be the real function defined as:

$\forall x \in \R_{>0}: \map f x = x^{1/x}$

Then $\map f x$ reaches its maximum at $x = e$ where $e$ is Euler's number .

## Source of Name

This entry was named for Jakob Steiner.