From: SourceForge.net <no...@so...> - 2004-09-19 20:25:43
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Bugs item #1030837, was opened at 2004-09-19 13:25 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: wrong results for integrate(sqrt(cos(x)+1)); Initial Comment: integrate(sqrt(cos(x)+1),x); ==> 2 SQRT(2) SIN(x) ------------------------------------ 2 SIN (x) (COS(x) + 1) SQRT(------------- + 1) 2 (COS(x) + 1) This is wrong! ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&group_id=4933 |
From: SourceForge.net <no...@so...> - 2004-11-01 22:32:50
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Bugs item #1030837, was opened at 2004-09-19 16:25 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: wrong results for integrate(sqrt(cos(x)+1)); Initial Comment: integrate(sqrt(cos(x)+1),x); ==> 2 SQRT(2) SIN(x) ------------------------------------ 2 SIN (x) (COS(x) + 1) SQRT(------------- + 1) 2 (COS(x) + 1) This is wrong! ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2004-11-01 17:32 Message: Logged In: YES user_id=28849 Why is this wrong? If I differentiate the result, I get: trigsimp(diff(%,x)); (%o35) -(sqrt(2)*sin(x)^2-2*sqrt(2)*cos(x)-2*sqrt(2)) /((cos(x)+1)*sqrt(2*cos(x)+2)) (%i36) factor(%); (%o36) -(sin(x)^2-2*cos(x)-2)/(cos(x)+1)^(3/2) (%i37) ev(%,sin(x)^2=1-cos(x)^2); (%o37) -(-cos(x)^2-2*cos(x)-1)/(cos(x)+1)^(3/2) (%i38) factor(%); (%o38) sqrt(cos(x)+1) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&group_id=4933 |
From: SourceForge.net <no...@so...> - 2006-02-23 17:37:49
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Bugs item #1030837, was opened at 2004-09-19 16:25 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&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: None Group: None >Status: Closed >Resolution: Invalid Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: wrong results for integrate(sqrt(cos(x)+1)); Initial Comment: integrate(sqrt(cos(x)+1),x); ==> 2 SQRT(2) SIN(x) ------------------------------------ 2 SIN (x) (COS(x) + 1) SQRT(------------- + 1) 2 (COS(x) + 1) This is wrong! ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2006-02-23 12:37 Message: Logged In: YES user_id=28849 Closing this report. The derivative matches the integrand, after some manipulations. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2004-11-01 17:32 Message: Logged In: YES user_id=28849 Why is this wrong? If I differentiate the result, I get: trigsimp(diff(%,x)); (%o35) -(sqrt(2)*sin(x)^2-2*sqrt(2)*cos(x)-2*sqrt(2)) /((cos(x)+1)*sqrt(2*cos(x)+2)) (%i36) factor(%); (%o36) -(sin(x)^2-2*cos(x)-2)/(cos(x)+1)^(3/2) (%i37) ev(%,sin(x)^2=1-cos(x)^2); (%o37) -(-cos(x)^2-2*cos(x)-1)/(cos(x)+1)^(3/2) (%i38) factor(%); (%o38) sqrt(cos(x)+1) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1030837&group_id=4933 |