What is the Maclaurin series for e^(-x)?

1 Answer
Nov 3, 2017

e^(-x) = 1 -x +(x^2)/(2!) - (x^3)/(3!) + x^4/(4!) - ...

Explanation:

We can start with the well known series for e^(x)

e^x = 1 +x +(x^2)/(2!) + (x^3)/(3!) + (x^4)/(4!) + ...

If we replace x in the above series by -x we get:

e^(-x) = 1 +(-x) +((-x)^2)/(2!) + ((-x)^3)/(3!) + ((-x)^4)/(4!) + ...
\ \ \ \ \ \ = 1 -x +(x^2)/(2!) - (x^3)/(3!) + x^4/(4!) - ...