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Re: Integrate...

  • To: mathgroup at smc.vnet.net
  • Subject: [mg44298] Re: Integrate...
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Tue, 4 Nov 2003 03:24:51 -0500 (EST)
  • Organization: Universitaet Leipzig
  • References: <bo5sl7$nr$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

don't mix approximated numbers like 1.0 with symbolic
computations.
Use Rationalize[] to make exact numbers
if you only have floating points.

Regards
  Jens

Sampo Smolander wrote:
>
> Does anybody know why
>
>    Integrate[Abs[1.0*Cos[r] + 1.0*Sin[r]], {r, 2.35, 2.36}]
>
> gives
>
>    -2.82839
>
> whereas without those 1.0's,
>
>    Integrate[Abs[Cos[r] + Sin[r]], {r, 2.35, 2.36}]
>
> gives the correct
>
>    0.000037373
>
> ?
>
> (I'm running Mathematica 4.1 on win98.)
>
> --
> Sampo Smolander ............... http://www.cs.helsinki.fi/u/ssmoland/
> Rolf Nevanlinna Institute, University of Helsinki ...................

~
~


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