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Re: Integrate question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg82307] Re: Integrate question
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Wed, 17 Oct 2007 04:04:44 -0400 (EDT)
  • Organization: The Open University, Milton Keynes, UK
  • References: <ff1pru$924$1@smc.vnet.net>

Oskar Itzinger wrote:

> Mathematica 5.2 under IRIX complains that
> 
> Integrate[x/(3 x^2 - 1)^3,{x,0,1}]
> 
> doesn't converge on [0,1].
> 
> However, Mathematica 2.1 under Windows gives the corrrect answer, (1/16).
> 
> When did Mathematica lose the ability to do said integral?

FWIW, Mathematica for Windows 5.2 as well as 6.0.1 cannot do it either, 
although it does not seem that hard to get the correct answer (the 
indefinite integral and the limits are evaluated in a breeze).

In[1]:= int = Integrate[x/(3 x^2 - 1)^3, x]

Out[1]= -(1/(12 (-1 + 3 x^2)^2))

In[2]:= Limit[int, x -> 1] - int /. x -> 0

Out[2]= 1/16

Regards,
-- 
Jean-Marc



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