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MathGroup Archive 2001

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Bug in Integrate?

  • To: mathgroup at
  • Subject: [mg28428] Bug in Integrate?
  • From: Ignacio Rodriguez <ignacio at>
  • Date: Wed, 18 Apr 2001 03:23:31 -0400 (EDT)
  • Organization: UCM
  • Sender: owner-wri-mathgroup at

    I am getting strange results when trying to perform an integral
using Integrate and I would like some advice about whether it is a bug
or I am making some mistake.
    The version of Mathematica I am using is "Microsoft Windows 3.0
(April 25, 1997)".
    The code used to calculate the integral is


    Then, I try different values of a for different settings of x,y,z.

    Trying a[0,0,z] gives {0,0,0}, a result which is clearly correct.

    Trying a[x,0,z] or a[0,y,z] gives a result in terms of elliptic
integrals, a result which seems correct. Particular examples are

    a[1/2,0,0]={0,2(EllipticE[-8]-5EllipticK[-8]),0} N[%]={0,-1.74631,0}


    Last of all, trying the general case gives the surprising result
a[x,y,z]={0,0,0}, a result which seems incorrect. Or at least, it seems
inconsistent with the previous results.
    Any hint to explain what is happening here will be greatly


Ignacio Rodriguez Ramirez de Arellano
Unidad de RMN
Universidad Complutense
Paseo Juan XXIII, 1
Madrid 28040, Spain

Tel. 34-91-394-3288
Fax  34-91-394-3245
e-mail: ignacio at

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