From: SourceForge.net <no...@so...> - 2005-11-29 19:08:57
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Bugs item #1369451, was opened at 2005-11-29 13:08 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=1369451&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: Open Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: secant & trigexpand Initial Comment: I believe the correct trigexpanded expression for sec (x+y) is (%o104) -(csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) But Maxima gives (%i105) sec(x+y),trigexpand; (%o105) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) Testing for x = 1 and y = 1 verifies Maxima makes a sign error for trigexoand(sec(x+y)): (%i106) sec(x+y),trigexpand; (%o106) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) (%i107) subst([x=1,y=1],%); (%o107) (csc(1)^2*sec(1)^2)/(sec(1)^2-csc(1)^2) (%i108) float(%); (%o108) 2.4029979617223818 (%i109) sec(2.0); (%o109) -2.4029979617223809 Barton ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1369451&group_id=4933 |
From: SourceForge.net <no...@so...> - 2005-11-30 03:24:14
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Bugs item #1369451, was opened at 2005-11-29 14:08 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1369451&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: Open Resolution: None Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: secant & trigexpand Initial Comment: I believe the correct trigexpanded expression for sec (x+y) is (%o104) -(csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) But Maxima gives (%i105) sec(x+y),trigexpand; (%o105) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) Testing for x = 1 and y = 1 verifies Maxima makes a sign error for trigexoand(sec(x+y)): (%i106) sec(x+y),trigexpand; (%o106) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) (%i107) subst([x=1,y=1],%); (%o107) (csc(1)^2*sec(1)^2)/(sec(1)^2-csc(1)^2) (%i108) float(%); (%o108) 2.4029979617223818 (%i109) sec(2.0); (%o109) -2.4029979617223809 Barton ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2005-11-29 22:24 Message: Logged In: YES user_id=28849 Not 100% sure, but in csc\Sec-plus (we should change that name to csc/sec-plus) the last line says (sin\Cos-plus l n f1 f2 flag))) If we change it to read (sin\Cos-plus l n f2 f1 flag))) we get the right answer. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1369451&group_id=4933 |
From: SourceForge.net <no...@so...> - 2005-12-09 01:52:41
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Bugs item #1369451, was opened at 2005-11-29 14:08 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1369451&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: Fixed Priority: 5 Submitted By: Barton Willis (willisbl) Assigned to: Nobody/Anonymous (nobody) Summary: secant & trigexpand Initial Comment: I believe the correct trigexpanded expression for sec (x+y) is (%o104) -(csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) But Maxima gives (%i105) sec(x+y),trigexpand; (%o105) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) Testing for x = 1 and y = 1 verifies Maxima makes a sign error for trigexoand(sec(x+y)): (%i106) sec(x+y),trigexpand; (%o106) (csc(x)*sec(x)*csc(y)*sec(y))/(sec(x)*sec(y)- csc(x)*csc(y)) (%i107) subst([x=1,y=1],%); (%o107) (csc(1)^2*sec(1)^2)/(sec(1)^2-csc(1)^2) (%i108) float(%); (%o108) 2.4029979617223818 (%i109) sec(2.0); (%o109) -2.4029979617223809 Barton ---------------------------------------------------------------------- >Comment By: Raymond Toy (rtoy) Date: 2005-12-08 20:52 Message: Logged In: YES user_id=28849 Suggested fix applied. ---------------------------------------------------------------------- Comment By: Raymond Toy (rtoy) Date: 2005-11-29 22:24 Message: Logged In: YES user_id=28849 Not 100% sure, but in csc\Sec-plus (we should change that name to csc/sec-plus) the last line says (sin\Cos-plus l n f1 f2 flag))) If we change it to read (sin\Cos-plus l n f2 f1 flag))) we get the right answer. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1369451&group_id=4933 |