Definition:Euler's Number/Base of Exponential

Definition
There is a number $x \in \R$ such that:
 * $\displaystyle \lim_{h \to 0} \frac{ x^{h} - 1 }{ h } = 1$

This number is called Euler's Number and is denoted $e$.

Also see

 * Equivalence of Definitions of Euler's Number