On Sunday, January 22, 2017 at 4:13:53 PM UTC, William wrote: > > On Sun, Jan 22, 2017 at 7:14 AM, Peleg Michaeli <free...@gmail.com > <javascript:>> wrote: > > Hi, > > > > sage: ((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x)).limit(x=infinity) > > -Infinity > > > > This is a wrong answer. It should be 2. > > > > Replacing 3/2 in the power by 1, 2, or 3 (at least) gives correct > answers > > (2, inf, inf). Replacing it by 5/2 given a wrong answer again. > > > > Is this related to a known bug? > > I don't know if it is known - - you can try searching > https://trac.sagemath.org/, which lists all bugs we know of. > > This is actually a bug in **MAXIMA**, which Sage calls to do this > limit: http://maxima.sourceforge.net/ >
no, it's not in Maxima 5.39.0 (see https://trac.sagemath.org/ticket/18920 and give it a positive review :-)) called with its default settings. $ sage --maxima ;;; Loading #P"/home/dima/Sage/sage-dev/local/lib/ecl/sb-bsd-sockets.fas" ;;; Loading #P"/home/dima/Sage/sage-dev/local/lib/ecl/sockets.fas" ;;; Loading #P"/home/dima/Sage/sage-dev/local/lib/ecl/defsystem.fas" ;;; Loading #P"/home/dima/Sage/sage-dev/local/lib/ecl/cmp.fas" Maxima 5.39.0 http://maxima.sourceforge.net using Lisp ECL 16.1.2 Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. The function bug_report() provides bug reporting information. (%i1) limit((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x),x,inf); (%o1) 2 Although calling this version of Maxima as sage: ((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x)).limit(x=infinity) gives -Infinity, still, as it's not called with default settings, but with something that breaks it sometimes. > If you call sympy instead it gets the right answer: > > sage: ((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x)).limit(x=infinity, > algorithm="sympy") > 2 > > sage: ((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x)).limit(x=infinity, > algorithm="maxima_taylor") > -Infinity > > sage: ((2^(2*x+1)+(2^x*x^100)^(3/2))/(4^x-100*2^x)).limit(x=infinity, > algorithm="maxima") > -Infinity > > > > > > > > > Thanks, > > Peleg. > > > > -- > > You received this message because you are subscribed to the Google > Groups > > "sage-support" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to sage-support...@googlegroups.com <javascript:>. > > To post to this group, send email to sage-s...@googlegroups.com > <javascript:>. > > Visit this group at https://groups.google.com/group/sage-support. > > For more options, visit https://groups.google.com/d/optout. > > > > -- > William (http://wstein.org) > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
