Okay, the equation is $\frac{2s^3-2s}{(4s^2-4s+5)^2}$
So I use partial fractions with $\frac{As+B}{4s^2-4s+5} + \frac{Cs+D}{(4s^2-4s+5)^2} = 2s^3-2s$
and square that quadratic get $(As+B)(16s^4-32s^3+56s^2-40s+25)+(Cs+D)(4s^2-4s+5) = 2s^3-2s$
This is the part where I'm suppose to plug in values for s to solve for the variables. But the only one that would make part of it $=0$ would make all terms $=0$.
So I tried differentiating both sides some times, each time picking a easy value for s that would equate one variable to $0$. Then I end up with a system of equations to solve, but get the wrong answer. I don't know what I'm doing wrong. Would someone point out what I did wrong or try solving it for me and writing the system of equations they get?
Thanks!