[Maxima-bugs] [ maxima-Bugs-1102908 ] limit/atan/exp returns complex expr with wrong principal val

[SourceForge.net <no...@so...>]

Bugs item #1102908, was opened at 2005-01-15 08:08
Message generated for change (Settings changed) made by macrakis
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1102908&group_id=4933

Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Daniel van Leeuwen (laeusen)
Assigned to: Nobody/Anonymous (nobody)
>Summary: limit/atan/exp returns complex expr with wrong principal val

Initial Comment:
Maxima version: 5.9.1
Maxima build date: 14:17 9/30/2004
host type: i686-redhat-linux-gnu
lisp-implementation-type: CLISP
lisp-implementation-version: 2.33.2 (2004-06-02) (built
on sting.unl.edu [129.93.181.39])

(C1) limit(atan(x)/(1/exp(1)-exp(-(1+x)^2)),x,inf,plus);
                                %E %I LOG(- 1)
(D1)                           --------------
                                      2

/* Since LOG(-1) equals %I*%PI, this should be the same
as */

(C2) subst(%I*%PI,log(-1),%th(1));
                                     %E %PI
(D2)                              - ------
                                       2

/* But doing the calculation step-by-step */

(C3) limit(atan(x),x,inf);
                                      %PI
(D3)                                 ---
                                       2
(C4) limit(-(x+1)^2,x,inf);
(D4)                                MINF
(C5) limit(exp(-(x+1)^2),x,inf);
(D5)                                  0

/* shows that the solution should be:
 *
 * exp(1)*%pi/2
 *
 */

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1102908&group_id=4933