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Re: A negative volume!

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  • Subject: Re: A negative volume!
  • From: ags at (Dave Seaman)
  • Date: Sat, 14 Mar 92 11:38:19 -0500

>> >Anybody have any suggestions on how to avoid this kind of problem?
>> A change in the order of integration seems to do the trick.  
>Doing the integral by hand also does the trick.  I think the question
>is how to increase the reliability of Mathematica's definite
>integrals, not to get the answer to one particular integral.

I fail to see any practical difference between the observations "A change in
order works." and "Integrating by hand words."  Both point out in unmistakeable
terms that there is a problem in Integrate[], and neither offers a solution.

My observation was intended to offer some insight into what went wrong.  More
precisely, the original poster has pointed out that the third integral in his
computation leads to an antiderivative that is piecewise continuous, with
discontinuities at both endpoints of the interval of integration, and
Mathematica seems to have used the wrong one-sided limits.


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