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Student Support Forum: 'Different results for the same Fourier Transform' topicStudent Support Forum > General > "Different results for the same Fourier Transform"

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Rainer
05/26/11 06:22am

Hello

I currently work on some Fourier transformations with mathematica and stumbled onto something strange while doing so.

I started a new kernel/notebook and entered

FourierTransform[Cos[p^2] Sin[p^2]/p, p, x]

The solution was

1/2 I Sqrt[\[Pi]/2] FresnelC[x/(2 Sqrt[\[Pi]])] -
1/2 I Sqrt[\[Pi]/2] FresnelS[x/(2 Sqrt[\[Pi]])]

and this seems right to me. In the next input I added an factor:

FourierTransform[Cos[a p^2] Sin[p^2]/(p), p, x]

Now the result was 0. If I assign a value to a, e.g. 1 or 2 I get a normal result but with a variable this transforms to zero. I also tried some Assumptions like making a real number or bigger then zero but nothing helped, the result is still zero.

Has anybody an idea why mathematica sais this Fourier transform is zero with a prefactor?

Thanks in advance

Rainer

P.S.: I'm working with mathematica 7.0.1.0. and on SUSE 11.3

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Subject (listing for 'Different results for the same Fourier Transform')
Author Date Posted
Different results for the same Fourier Transform Rainer 05/26/11 06:22am
Re: Different results for the same Fourier Tran... Sjoerd C . d... 05/30/11 3:34pm
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