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From: SourceForge.net <noreply@so...>  20040722 16:31:38

Bugs item #996023, was opened at 20040722 09:31 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=996023&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: a result of a differential equation is wrong Initial Comment: the solution of the differential equation (1+x)*'diff(y,x)+y=1+log(1+x); is %C/(1+x)+log(1+x). The command ode2(%,y,x)returns the following solution : y=((x+1)log(x+1)+%C1)/(x+1). It looks like there's an error of sign (with the 1 which multiplicate the constant %C)  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=996023&group_id=4933 
From: SourceForge.net <noreply@so...>  20040725 13:22:20

Bugs item #996023, was opened at 20040722 11:31 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=996023&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: a result of a differential equation is wrong Initial Comment: the solution of the differential equation (1+x)*'diff(y,x)+y=1+log(1+x); is %C/(1+x)+log(1+x). The command ode2(%,y,x)returns the following solution : y=((x+1)log(x+1)+%C1)/(x+1). It looks like there's an error of sign (with the 1 which multiplicate the constant %C)  >Comment By: Barton Willis (willisbl) Date: 20040725 08:22 Message: Logged In: YES user_id=895922 This is not a bug; both solutions are correct. In Maxima's solution substitute %c > %c + 1. This makes the two solutions identical. Since %c is an arbitrary parameter, the substitution %c > %c + 1 is okay. Suggestion: learn how to substitute a putative solution to an equation (DE or algebraic) into the equation to check if it is correct. Barton  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=996023&group_id=4933 
From: SourceForge.net <noreply@so...>  20040727 02:01:18

Bugs item #996023, was opened at 20040722 11:31 Message generated for change (Settings changed) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=996023&group_id=4933 Category: None Group: None >Status: Closed Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: a result of a differential equation is wrong Initial Comment: the solution of the differential equation (1+x)*'diff(y,x)+y=1+log(1+x); is %C/(1+x)+log(1+x). The command ode2(%,y,x)returns the following solution : y=((x+1)log(x+1)+%C1)/(x+1). It looks like there's an error of sign (with the 1 which multiplicate the constant %C)  Comment By: Barton Willis (willisbl) Date: 20040725 08:22 Message: Logged In: YES user_id=895922 This is not a bug; both solutions are correct. In Maxima's solution substitute %c > %c + 1. This makes the two solutions identical. Since %c is an arbitrary parameter, the substitution %c > %c + 1 is okay. Suggestion: learn how to substitute a putative solution to an equation (DE or algebraic) into the equation to check if it is correct. Barton  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=996023&group_id=4933 