# Maclaurin series

## Homework Statement

find $$a_{n}$$ for $$f(x)\ =\ \frac{1}{1+3x}$$

## The Attempt at a Solution

I got:
f(0) = 1
f'(0) = -3
f''(0) = 9

The answer I ended up with was:
$$a_{n} \ = \ {(-1)}^n\frac{3^n}{n!}$$

However, the answer in the back of my book has the same answer except it's not divided by n!.