Re: Integration - another Integer as a result
- To: mathgroup at smc.vnet.net
- Subject: [mg93784] Re: [mg93743] Integration - another Integer as a result
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Tue, 25 Nov 2008 07:20:50 -0500 (EST)
- Reply-to: hanlonr at cox.net
This integral evaluates on versions 5.2, 6.0.3, and 7 under Mac OS
Integrate[2 x Sin[n Pi x / l] Sin[k Pi x / l], x]
(l*((l*Cos[((k - n)*Pi*x)/l] +
(k - n)*Pi*x*Sin[((k - n)*Pi*x)/l])/
(k - n)^2 -
(l*Cos[((k + n)*Pi*x)/l] +
(k + n)*Pi*x*Sin[((k + n)*Pi*x)/l])/
(k + n)^2))/Pi^2
$Version
7.0 for Mac OS X x86 (64-bit) (November 11, 2008)
Integrate[2 x Sin[n Pi x / l] Sin[k Pi x / l], x]
(l*((Pi*x*(k - n)*Sin[
(Pi*x*(k - n))/l] +
l*Cos[(Pi*x*(k - n))/l])/
(k - n)^2 -
(Pi*x*(k + n)*Sin[
(Pi*x*(k + n))/l] +
l*Cos[(Pi*x*(k + n))/l])/
(k + n)^2))/Pi^2
Bob Hanlon
---- MikeSw <sowasowa at o2.pl> wrote:
=============
Hello,
I'm trying to calculate an integer using Mathematica, but instead of getting a "normal" result I get another Integer. The algorithm available on Wolfram website does this calculation with no problem:
http://img156.imageshack.us/my.php?image=cakaqt6.jpg
but Mathematica gives this:
http://img156.imageshack.us/my.php?image=cakamtkmvk9.jpg
I guess there is something wrong with the input?
--
Bob Hanlon
