Find the first three terms of the Maclaurin series for `xe^(-x)` Consider that it is centered at x = 0.
Maclaurin series of infinitely differentiable function `f` is defined as
`f(0)=0e^0=0` <-- First term
`1/(1!)x=x` <-- Second term
`-2/(2!)x^2=-x^2` <-- Third term