# Maclaurin Series

## Homework Statement

(1 pt) Compute the 9th derivative of:
f(x) = $$\frac{cos(6x^4)-1}{x^7}$$
at x=0.

## Homework Equations

Hint: Use the MacLaurin series for f(x).

## The Attempt at a Solution

I have tried many weird ways and cannot come up with the correct numerical answer. I've gotten 0 each time and it still comes up as wrong. Please help point me in the correct direction, even if it is only a verbal explanation!

Thanks so much