e
This is an old revision of this page, as edited by WilliamKH (talk | contribs) at 18:34, March 18, 2012. It may differ significantly from current revision.
e is a useful mathematical constant which is a transcendental number approximately equal to 2.718281828459045 . e can be used in logarithms as the base, called a natural logarithm. e is named for Swiss mathematician Leonhard Euler, though he did not discover the constant.
It has some remarkable properties. For example:
- <math>\frac{d}{dx}e^x = e^x.</math>
(i.e. the exponetial function is an eigenfunction of the derivative operator, with eigenvalue 1).
Formulae for e
- With limits - <math>e=\lim_{x\to\infty}\left(1+\frac{1}{x}\right)^x</math>
- With infinite series - <math>e=\sum_{n=0}^{\infty}\frac{1}{n!}</math>