This is now Trac#27076 <https://trac.sagemath.org/ticket/27076#ticket>. Not yet reported upstream (I have to finde a way to recover access toi the damn sourceforge site...).
As far as I can tell, this bug is distinct from all bugs reported against desolve ; a cursoly look at othe "symbolics" tickets did not raise this exact error, but I may have been mistaken : pleas feel free to correct me... Thanks to Thrash for taking the time to formally report the bug. HTH, Le mercredi 16 janvier 2019 19:05:59 UTC+1, Thrash a écrit : > > As advised in the thread > > > https://ask.sagemath.org/question/45046/wrong-solutionoutput-for-differential-equation/ > > I'm opening this one now. > > > When running the following code, one obtains a wrong output: > > y=function('y')(x) > desolve(diff(y)==4*y/x+x*sqrt(y),y,ics=[1,1]).factor() > > The output is > 1/4*x^4*(log(x) - 2)^2 > instead of > 1/4*x^4*(log(x) + 2)^2 > . Mathematica however outputs both (by running > DSolve[{D[y[x], x] == 4*y[x]/x + x*Sqrt[y[x]], y[1] == 1}, y[x], x] > ). > > > Giac also gives the right answer: > sage: giac("desolve([y'=4*y/x+x*sqrt(y),y(1)=1],y)").sage() > [1/4*(ln(x) + 2)^2*e^(4*ln(x))] > . > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
