# Inverse laplace transform

1. Feb 2, 2013

### izen

1. The problem statement, all variables and given/known data

find the inverse laplace transformation of $\frac{5s+4}{s^2}$ e$^{-2s}$

2. Relevant equations

3. The attempt at a solution

I have tried to partial fractions $\frac{5s+4}{s^2}$ and I got $\frac{5}{s}$+$\frac{4}{s^2}$ and I know that the answer must have u(t-2) because of second shifting ( a=2)

but I looked at the answer from this question is 5 u(t-2)(e$^{4(t-2)}$ - e$^{-(t-2)}$).

2. Feb 3, 2013

### vela

Staff Emeritus

3. Feb 3, 2013

thank you

4. Feb 3, 2013

### Ray Vickson

First: what is the inverse Laplace transform of $(5s+4)/s^2$? Next: worry about the effect of the factor $e^{-2s}$.

5. Feb 3, 2013

### vela

Staff Emeritus
Yes, that's correct.

6. Feb 4, 2013

### izen

Thanks you all