integrate



Hi David,

     Thanks for the suggestion.  Here are the results.
It evaluates the limit correctly when one takes the limit
directly as seen below,

**********
(C1) numer:true
;

(D1)                                 TRUE
(C2) limit(tan(x+%pi/4),x,0,minus);

(D2)                                  1.0
(C3) 
**********

but when one tries to integrate(1/cos(x)^2,x,0,%PI/4) it
still chokes on the divide by zero error.  (See below.)

**********
(C1) numer:true;

(D1)                                 TRUE
(C2) integrate(1/cos(x)^2,x,0,%PI/4);


RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 1.570796326794897 by 51819//32989 = 1.570796326048077

RAT replaced 1.570796326048077 by 51464//32763 = 1.570796325122852

RAT replaced -3.05222354485242E-5 by -1//32763 = -3.05222354485242E-5

RAT replaced -1.57079632512285 by -51109//32537 = -1.57079632418477

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced -0.7853981607873 by -25022//31859 = -0.7853981606453

RAT replaced 1.570796324184774 by 50754//32311 = 1.570796323233574

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 0.78539816339745 by 25732//32763 = 0.78539816256143

RAT replaced 6.283185307179586 by 103993//16551 = 6.283185306023805
Division by 0
 -- an error.  Quitting.  To debug this try DEBUGMODE(TRUE);)
(C3)
**********

Something may have gone wrong with the original build.  Looks like
a precision problem.  What processor are you running on?  Mine is 
in the Athlon Thunderbird series.


Cheers,
Lee




David Holmgren wrote:
> 
> Hi - I got the limit to evaluate by using numer:true !
> 
>  Dave Holmgren
> 
> > -----Original Message-----
> > From: Lee Rottler [SMTP:rottler at emerald]
> > Sent: Wednesday, January 16, 2002 4:33 PM
> > To:   michel.gosse@freesbee.fr
> > Cc:   maxima@www.ma.utexas.edu
> > Subject:      Re: [Maxima] integrate
> >
> > Hello,
> >
> > This is what happened when I tried it under maxima5.6 with gcl.
> >
> > ***************
> > (C2) integrate(1/cos(x)^2,x,0,%PI/4);
> >
> > Division by 0
> >  -- an error.  Quitting.  To debug this try DEBUGMODE(TRUE);)
> > (C3)
> > ***************
> >
> > On the other hand I built both gcl and maxima from sources on
> > the old UT site so if someone has a patch for this please let me
> > know.   Thanks.
> >
> > Cheers,
> > Lee
> >
> > Gosse Michel wrote:
> > >
> > > Hello
> > >
> > > With maxima 5.6, the following command :
> > >
> > > integrate(1/cos(x)^2,x,0,%PI/4);
> > > give the answer :
> > > lim(x->0) tan(x+%PI/4)
> > >
> > > I would expect that maxima returns the real 1, because it is a very
> > > classical function to integrate.
> > >
> > > Best regards
> > >
> > > ****************************
> > > Michel Gosse
> > > michel.gosse@ac-poitiers.fr
> > > michel.gosse@freesbee.fr
> > > ****************************
> > > _______________________________________________
> > > Maxima mailing list
> > > Maxima@www.math.utexas.edu
> > > http://www.math.utexas.edu/mailman/listinfo/maxima
> >
> > --
> > * Lee Rottler                                  rottler@es.ucsc.edu     *
> > * System Administrator/Scientific Programmer   Office:  (831) 459-5059 *
> > * High Performance Computing                   FAX:     (831) 459-3074 *
> > * IGPP - Earth Sciences                                                *
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-- 
* Lee Rottler                                  rottler@es.ucsc.edu     *
* System Administrator/Scientific Programmer   Office:  (831) 459-5059 *
* High Performance Computing                   FAX:     (831) 459-3074 *
* IGPP - Earth Sciences                                                *