# I really need help with this fourier transform please

1. Apr 6, 2009

### skullofchaos

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

an exponentially decaying sinusoid is defined as

f (t) = a exp (-t/towel) exp (i2(pie)vt) ; t greater than or equal to 0
0 ; t less than zero

2. Relevant equations

i have to show that its fourier transform is

F(v) = a/(2(pie)j(v-v0) + (1/towel))

3. The attempt at a solution

i dont know where to start, thnx to all who help

Last edited: Apr 6, 2009
2. Apr 7, 2009

### tiny-tim

Welcome to PF!

Hi skullofchaos! Welcome to PF!

(it's spelt tau, not towel! oh, and have one: τ and a pi: π and a ≥ )

Hint: use the convolution formula.

3. Apr 12, 2009

### skullofchaos

i am in 2nd year uni and i have not done any university maths so i am not sure what to do, this question is on my physics assignment

4. Apr 13, 2009

### tiny-tim

5. Apr 13, 2009

### skullofchaos

thnx for the reply, but sorry, none of it makes sense to me, um, what do i have to start with and my maths is a bit rusty (i have not done maths since year 12)

6. Apr 13, 2009

### tiny-tim

well, how much do you know?

the question says "show that its fourier transform is …"

do you know what a fourier transform is?

7. Apr 13, 2009

### skullofchaos

we did not do much on fourier transforms and the lecture notes and text book dont really help at all. i know how to integrate and differentiate - basic differential calculus

8. Apr 13, 2009

### tiny-tim

well, you'll need to do extensive reading on fourier transforms then …

it's a whole subject in itself, and not the sort of thing we can give a quick introduction to

try wikipedia first, and then your text book (which book is it?) … if that isn't enough, you'll need to find a better text book