Different results with FourierTransform[]

*To*: mathgroup at smc.vnet.net*Subject*: [mg97588] Different results with FourierTransform[]*From*: Wieland Brendel <wielandbrendel at gmx.net>*Date*: Mon, 16 Mar 2009 04:24:44 -0500 (EST)

Dear reader, I somewhat stumbled over the following behaviour of mathematica: I tried to calculate the fouriertransform of Tanh[x]. I did this in two ways: 1. Directly: InverseFourierTransform[Tanh[x], x, p] 2. Indirectly: InverseFourierTransform[Tanh[B x], x, p] where I set B -> 1 in the end. However, the result between the two approaches differs: Whereas in the first approach I get a complex number (with both real and imaginary part being non-zero for almost all values of p), the result in the second approach yields NO real part; the imaginary part however is the same as in the first approach. Is there any explanation for this behaviour? Thanks a lot in advance! I am really stuck with that... Wieland

**Follow-Ups**:**Re: Different results with FourierTransform[]***From:*Richard Hofler <rhofler@bus.ucf.edu>