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Re: How to swap real and imaginary parts and changing signs using Integrate

  • To: mathgroup at smc.vnet.net
  • Subject: [mg117700] Re: How to swap real and imaginary parts and changing signs using Integrate
  • From: Simon <simonjtyler at gmail.com>
  • Date: Wed, 30 Mar 2011 04:09:39 -0500 (EST)
  • Reply-to: comp.soft-sys.math.mathematica at googlegroups.com

The same thing happens if you do the integral in Wolfram|Alpha.
Type in:
integral arctanh(x)sin(pi x) x^(-3/2) from -infty to infty
and you get the numeric answer
0.443743+1.24745 i
Tell it to evaluate with more time and you get the closed form
1/3 (-1)^(1/4) pi^2 (4 _2 F_3(1/2, 1;5/4, 3/2, 7/4;-pi^2/4)-(6-6 i) C(sqrt(2))-3 i)
= -1.25202-0.4455 i

Nate that there's a overall factor of the 4th root of -1.
This could explain the factor of i -- the wrong root was chosen somewhere.


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