domain complex leads to incorrect integral

[rtoy]

Imported from SourceForge on 2024-07-08 01:46:53 Created by kcrisman on 2019-06-28 01:10:07 Original: https://sourceforge.net/p/maxima/bugs/3566

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Maxima 5.42.2 http://maxima.sourceforge.net
using Lisp ECL 16.1.2
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) display2d:false;

(%o1) false
(%i2) domain:complex;

(%o2) complex
(%i3) integrate(acos(cos(x)/(2*cos(x)+1)),x);

(%o3) 2*atan(sin(x)/(cos(x)+1))
       *acos((1-sin(x)^2/(cos(x)+1)^2)/((sin(x)^2/(cos(x)+1)^2+1)
                                       *((2*(1-sin(x)^2/(cos(x)+1)^2))
                                        /(sin(x)^2/(cos(x)+1)^2+1)
                                        +1)))

According to calculations at Sage Trac 26138, this is an incorrect primitive.

[rtoy]

Imported from SourceForge on 2024-07-08 01:46:54 Created by robert_dodier on 2019-09-01 05:22:11 Original: https://sourceforge.net/p/maxima/bugs/3566/#dfb8

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• labels: --> integrate, domain, complex

[rtoy]

Imported from SourceForge on 2024-07-08 01:46:57 Created by robert_dodier on 2019-09-01 05:22:11 Original: https://sourceforge.net/p/maxima/bugs/3566/#7c55

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Thanks for the report. If I am not mistaken, there are a number of similar bugs which are triggered by domain: complex. It seems likely there is an underlying common cause, but I haven't investigated it.

[rtoy]

Imported from SourceForge on 2024-07-08 01:47:01 Created by kcrisman on 2019-09-03 15:52:29 Original: https://sourceforge.net/p/maxima/bugs/3566/#bf4c

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It seems likely there is an underlying common cause, but I haven't investigated it.

I am sure you are correct about that.

Thanks for looking into these various bugs as opportunity presents itself!