# Fourier transform

1. Apr 4, 2007

### kolycholy

how can I find fourier transform of 1/(1+4t^2)?
hmmm =/

2. Apr 4, 2007

### moe_3_moe

try to take x=2t and use the symmetry or duality property and then the scaling property

3. Apr 4, 2007

### antoker

Use the fact that your expression can be expressed as $$\int{\frac{f(t)}{g(t)}dx}$$, where $$f(t) = e^{-j\omega t}, g(t)=1+4t^{2}$$ and proceed as stated by the rule. If i remember it correctly it goes something like $$\frac{f'(t)g(t)-g'(t)f(t)}{g(t)^{2}}$$

Last edited: Apr 4, 2007
4. Apr 4, 2007

### Manchot

You've mixed up differentiation and integration...

5. Apr 4, 2007

### moe_3_moe

manchot is right ... so complicated ... i think the properties of the fourier transformation is better

6. Apr 4, 2007

### antoker

damn.... you're right ;)

7. Apr 4, 2007

### kolycholy

i tried taking a look at the fourier transform properties..
but hmm, still confused

8. Apr 5, 2007

### moe_3_moe

check the scaling and the symmetry property ... sorry i can't tell the answer ... it is the rules ...