I really with this fourier transform please

[skullofchaos]

Homework Statement

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

Homework Equations

i have to show that its Fourier transform is

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

The Attempt at a Solution

i don't know where to start, thnx to all who help

 

[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.

 

[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

 

[tiny-tim]

Hi skullofchaos!

i am in 2nd year uni and i have not done any university maths …

In that case, you'd better look at http://en.wikipedia.org/wiki/Fourier_transform#Properties_of_the_Fourier_transform, particularly about the convolution formula.

 

[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)

 

[tiny-tim]

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)

well, how much do you know?

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

do you know what a Fourier transform is?

 

[skullofchaos]

we did not do much on Fourier transforms and the lecture notes and textbook don't really help at all. i know how to integrate and differentiate - basic differential calculus

 

[tiny-tim]

we did not do much on Fourier transforms and the lecture notes and textbook don't really help at all. i know how to integrate and differentiate - basic differential calculus

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 textbook (which book is it?) … if that isn't enough, you'll need to find a better textbook