A bug of Integrate[] in Mathematica 4.1
- To: mathgroup at smc.vnet.net
- Subject: [mg27343] A bug of Integrate[] in Mathematica 4.1
- From: Rino Bandiera <bandiera at arcetri.astro.it>
- Date: Wed, 21 Feb 2001 03:17:26 -0500 (EST)
- Organization: Osservatorio Astrofisico di Arcetri
- Sender: owner-wri-mathgroup at wolfram.com
Hi!
While Mathematica 4.1 correctly solves the Integral:
Integrate[1 - x^a, {x, 0, 1}]
a
----
1 + a
it gets stuck with an Integral like:
Integrate[1 - x^(-9999/10000), {x, 0, 1}]
(i.e. an exponent close to -1, but as a fraction of 2 large integer
numbers)
Mathematica 3.0, instead, was working well on this point.
A related problem is for definite integrals like:
Integrate[1 - x^((5 - q)/2), {x, 0, 1}]
Here, while Mathematica 3.0 did not check on the allowed interval for
the parameter q, Mathematica 4.1
does, but giving incorrect results.
In fact the quote interval of validity is: Re[q]<2 (while it
should clearly be: Re[q]]<7)
Odd results come out for all this class of functions.
-------------
I have reported the problem to the Wolfram Support. The only result I
got are the following answers:
> Thank you for the report. Integrate[] appears to be behaving
erroneously in
> all of the cases you present. I have notified the the developers of
the
> problems. Unfortunately, there does not appear to be a workaround.
> Unfortunately, there are no bug lists available, and I will not be
informed
> of the status of the bug until it is fixed. Most likely, a patch will
not be
> made available.
Therefore, no solution is on the way, unfortunately. JUST BE CAREFUL!
Best
regards, Rino