Nearly identical to the Taylor Series used in Calculus, an approximation of a function. Unlike the Taylor Series, which can approximate a function around any number, the Maclaurin Series is specifically for approximating around 0.

The formula for finding the Maclaurin Series is:

Sigma (E)   f~n(0) xn  where f~n is the nth derivative of f
n=0            x!

Why is the Maclaurin series useful? This simple formula gives us a way to find polynomial approximations of many functions. This can be used to approximate the integral of f, among many other things.