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Re: Unexpected non-evaluation problem

• To: mathgroup at smc.vnet.net
• Subject: [mg63142] Re: Unexpected non-evaluation problem
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Thu, 15 Dec 2005 06:07:19 -0500 (EST)
• Organization: The Open University, Milton Keynes, UK
• References: <dnrch3$kie$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Carl Cotner wrote:
> I am totally baffled by the following Mathematica behavior:
> 
>   In[1]:= InverseFourierTransform[FourierTransform[x^2, x, y], y, x]
>   Out[1]= Sqrt[2 Pi] x^2 FourierTransform[DiracDelta[y], y, x]
> 
>   In[2]:= Sqrt[2 Pi] x^2 FourierTransform[DiracDelta[y], y, x]
>   Out[2]= x^2
> 
> I've already asked my local guru without success, so I'm hoping someone
> here can help me. Does anyone know why the first expression doesn't
> evaluate to x^2 all by itself? How I can force it to do so?
> 
> Carl
> 
Hi Carl,

Mapping *Evaluate* to all parts will do it. Why? I do not know...

In[1]:=
Evaluate //@ InverseFourierTransform[FourierTransform[x^2, x, y], y, x]

Out[1]=
x^2

Best regards,
/J.M.

• Follow-Ups:
  • Re: Re: Unexpected non-evaluation problem
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>