This post is to give some background about the constant e. Math students normally encounter e (2.7182818284590452…) in their Precalculus chapter on exponentials and logarithms, and they often wonder where this rather odd number comes from, and what is special about it.

It’s usually called Euler’s Identity, after the great Swiss mathematician Leonard Euler, and several polls of mathematicians and physicists have bestowed on it titles such as “the greatest equation ever”