# Laplace transformation

1. Dec 11, 2008

### leopard

How can I transform

$$F(s) = \frac{1}{(s-2)^2}$$

?

I cannot see that any of the functions in my table is useful...

2. Dec 11, 2008

### gabbagabbahey

Use the third one in the list along with the "frequency shifting rule": $$\mathcal{L}^{-1}[F(s-\alpha)]=e^{\alpha t}\mathcal{L}^{-1}[F(s)]$$

3. Dec 11, 2008

### HallsofIvy

Staff Emeritus
Actually, it's the second one in the list: the Laplace transform of 1/t is 1/s2. I think gabbagabbahey was counting the heading. Also note that gabbagabbahey's "frequency shifting rule" is implied in the third, the Laplace transform of eat is 1/(s-a) which is just the laplace transform of 1/t "shifted" by a.

4. Dec 11, 2008

### gabbagabbahey

Actually I meant the third (with n=1 of course)---but certainly the second is a little more straightforward!

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