# Homework Help: Converting from T-domain to S-domain?

1. Oct 10, 2009

### mhnassif

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

convert T-domain to S-domain

F(t)= e^-4t *sin10t

2. Relevant equations

3. The attempt at a solution

sin10t converted to 10/[(S^2)+100]

but how can i convert e^-4t ?

2. Oct 10, 2009

### ryan88

3. Oct 10, 2009

### mhnassif

Thank you,

I know exp(-at) on s-domain will be

But is the Alpha sign a constant, to replace it with a value?

4. Oct 10, 2009

### ryan88

I just took a closer look at that table, I'm not sure why they used a and alpha. Basically this should be:

$$\mathcal{L}\left(e^{-at})\right = \frac{1}{s+a}$$

Hope that helps,

Ryan

5. Oct 11, 2009

### mhnassif

Solved ,, Thank You ,

Have a nice day