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Bug with Integrate in v7?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg103116] Bug with Integrate in v7?
  • From: kostka <kostka at gmail.com>
  • Date: Tue, 8 Sep 2009 05:59:43 -0400 (EDT)

Okay it took me an hour to track this down, and the only explanation I
can see is that there is a bug in Mathematica v7 with Integral[] with
multiple bounds.

In v7.0 (answers should both be 512/27, only one of them is):

In[1]:= f = (x - 1)^2*(y - 1)^2*(z - 1)^2;
Integrate[f, {x, -1, 1}, {y, -1, 1}, {z, -1, 1}]
Integrate[Integrate[Integrate[f, {x, -1, 1}], {y, -1, 1}], {z, -1, 1}]

Out[2]= 0

Out[3]= 512/27


In v6.0 (correct behavior):

In[1]:= f = (x - 1)^2*(y - 1)^2*(z - 1)^2;
Integrate[f, {x, -1, 1}, {y, -1, 1}, {z, -1, 1}]
Integrate[
 Integrate[Integrate[f, {x, -1, 1}], {y, -1, 1}], {z, -1, 1}]

Out[2]= 512/27

Out[3]= 512/27


Serious bug, right?  Or am I missing something obvious?

Tim


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