# B Inverse Fourier transform?

1. Jul 30, 2017

### DesertFox

Hello buddies!
Tell me, please, are they mathematically correct or not?

I need a simple YES/NO answer.
I have not sufficient knowledge to understand them. I just need to know whether they are correct....

Thank you!!!

P.S. Am is amplitude; I guess it is a form of Fourier's inverse transform applied in electromagnetism...

2. Jul 30, 2017

### Staff: Mentor

What is the source of these equations?

3. Jul 30, 2017

### DesertFox

A russian handbook for electricians..

4. Jul 30, 2017

### Staff: Mentor

Is it this same book that we have discussed here previously?

5. Jul 30, 2017

### DesertFox

No. This one is from Russian source! Is it correct?

6. Jul 30, 2017

### Staff: Mentor

After the third equal sign the expression loses its dependence on t, so that seems wrong. The infinity/-infinity is not terribly meaningful either.

7. Jul 30, 2017

### mathman

You can simplify by taking $$Ame^{j\psi}$$ outside the integral sign.
The resultant integrand looks like the Fourier transform of the delta function.

8. Aug 1, 2017

### Dragon27

Are you sure you're copying it from the textbook correctly? Shouldn't amplitude $Am$ be with $m$ as a subscript (like in $A_m$ or something)? Can you just screenshot the page with equations (I doubt it is an actual screenshot from the textbook) or make a photo of it?
What is the name of the source and where in the source (page, equation number) one can find these equations?

Because it got buried in the notation like $\phi(f)=2\pi f_0 t + \psi$ (you can spot it somewhere at the end of this... mess). Not sure if it would help fully decipher it.

Last edited: Aug 1, 2017