I have reported this to the Maxima team. wdjo...@gmail.com schrieb am Donnerstag, 5. September 2024 um 15:19:02 UTC+2:
> On Thu, Sep 5, 2024 at 9:16 AM 'OHappyDay' via sage-support < > sage-s...@googlegroups.com> wrote: > >> I recently stumbled upon something that looks like a bug: >> >> Try to integrate the following function: >> >> f(x)=log(1-4*cos(x)+4) >> integrate(f,x,0,pi) >> >> According to the following video ( >> https://www.youtube.com/watch?v=nscSDYApAjM) the result should be >> >> 2*pi*log(2) >> >> But my local Sage as well as online I get this result: >> >> 1/12*I*pi^2 + pi*log(3) - 1/2*pi*log(9/4) + 1/2*I*log(2)^2 - I*dilog(2) + >> I*dilog(-1/2) + I*dilog(-2) >> >> which is a complex number instead. >> > > This could be a bug in Maxima: > > sage: CC(integrate(f,x,0,pi, algorithm='sympy')) > > 4.35517218060720 > > sage: CC(integrate(f,x,0,pi, algorithm='maxima')) > > 4.44089209850063e-16 - 3.28986813369645*I > > sage: CC(2*pi*log(2)) > 4.35517218060720 > > >> >> Similarly this function >> >> g(x)=log(1-cos(x)+1/4) >> integrate(g,x,0,pi) >> >> results in >> >> 1/12*I*pi^2 - pi*log(3) + 1/2*pi*log(9/4) + 1/2*I*log(2)^2 - I*dilog(2) + >> I*dilog(-1/2) + I*dilog(-2) >> >> although it should be ZERO. >> >> -- >> 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. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sage-support/d3714f3c-b193-4d32-9d44-8a5a6d8ec5f1n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sage-support/d3714f3c-b193-4d32-9d44-8a5a6d8ec5f1n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/29149ab9-97f6-4495-b355-6c40952dceb3n%40googlegroups.com.
