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## maxima-bugs

 [Maxima-bugs] [ maxima-Bugs-2834169 ] Wrong solution with sqrt/asin equation solving From: SourceForge.net - 2009-08-08 13:58:19 ```Bugs item #2834169, was opened at 2009-08-08 15:58 Message generated for change (Tracker Item Submitted) made by jyoberle You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2834169&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core - Solving equations Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Jean-Yves (jyoberle) Assigned to: Nobody/Anonymous (nobody) Summary: Wrong solution with sqrt/asin equation solving Initial Comment: I noticed that when using latest version of Maxima: solve(1-(asin(x^2-1))^2,x) gives [x=-sqrt(1-sin(1)),x=sqrt(1-sin(1)),x=-sqrt(sin(1)+1),x=sqrt(sin(1)+1)] which is correct. But: solve(sqrt(1-(asin(x^2-1))^2),x) gives [] whereas I would have expected same solutions as above. Below are details about the Maxima version: ------------------------------------------------------------- Maxima version: 5.18.1 Maxima build date: 20:57 4/19/2009 host type: i686-pc-mingw32 lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- Best regards, Jean-Yves ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2834169&group_id=4933 ```
 [Maxima-bugs] [ maxima-Bugs-2834169 ] Wrong solution with sqrt/asin equation solving From: SourceForge.net - 2010-07-10 15:29:10 ```Bugs item #2834169, was opened at 2009-08-08 15:58 Message generated for change (Settings changed) made by crategus You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2834169&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core - Solving equations Group: None >Status: Closed >Resolution: Fixed Priority: 5 Private: No Submitted By: Jean-Yves (jyoberle) Assigned to: Nobody/Anonymous (nobody) Summary: Wrong solution with sqrt/asin equation solving Initial Comment: I noticed that when using latest version of Maxima: solve(1-(asin(x^2-1))^2,x) gives [x=-sqrt(1-sin(1)),x=sqrt(1-sin(1)),x=-sqrt(sin(1)+1),x=sqrt(sin(1)+1)] which is correct. But: solve(sqrt(1-(asin(x^2-1))^2),x) gives [] whereas I would have expected same solutions as above. Below are details about the Maxima version: ------------------------------------------------------------- Maxima version: 5.18.1 Maxima build date: 20:57 4/19/2009 host type: i686-pc-mingw32 lisp-implementation-type: GNU Common Lisp (GCL) lisp-implementation-version: GCL 2.6.8 ------------------------------------------------------------- Best regards, Jean-Yves ---------------------------------------------------------------------- >Comment By: Dieter Kaiser (crategus) Date: 2010-07-10 17:29 Message: This problem is no longer present. We get for both examples: (%i2) solve((1-(asin(x^2-1))^2),x); (%o2) [x = -sqrt(1-sin(1)),x = sqrt(1-sin(1)),x = -sqrt(sin(1)+1), x = sqrt(sin(1)+1)] (%i3) solve(sqrt(1-(asin(x^2-1))^2),x); (%o3) [x = -sqrt(1-sin(1)),x = sqrt(1-sin(1)),x = -sqrt(sin(1)+1), x = sqrt(sin(1)+1)] I think this is because of revision 1.26 of solve.lisp. The algorithm has been improved to compare simplified expressions. Closing this bug report as fixed. Dieter Kaiser ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2834169&group_id=4933 ```