# Integral with e^-|t|

1. Nov 26, 2008

### sam.green

I am working through Signals and Systems Demystified on my own. I need to integrate:

$$\int_{-\infty}^{\infty}{sin(2t)e^{-|t|}e^{-j2\pi ft}} dt$$

I first went about dealing with the absolute value sign by using the following

$$\int_{-\infty}^{\infty} e^{-|t|} dt = \int_{-\infty}^{0} e^{t} dt + \int_{0}^{\infty} e^{-t} dt$$

Going along this route seems to not work and makes me think the expansion is incorrect. Can anyone give me a pointer?

Thanks,
Sam

2. Nov 26, 2008

### sam.green

The expansion is correct.

3. Nov 28, 2008

### rochfor1

Use the decomposition you have now and do integration by parts twice (on each decomposed integral). I think you'll be pleasantly surprised.

4. Dec 8, 2008

### sam.green

That worked. Thanks!