Quote Originally Posted by thedoge View Post
on 3...

I have it to
$\displaystyle
X(s) = \frac{-13s^3+4s-36}{s^2(s^2+13)}
$

Now do I do partial fractions like this?
$\displaystyle
X(s) = \frac{Ax+B}{s^2} + \frac{Cx+D}{s^2+13}
$
The correct form should be

$\displaystyle \frac{-13s^3+4s-36}{s^2(s^2+13)}=\frac{A}{s}+\frac{B}{s^2}+\frac{C s+D}{s^2+13}$