What does "set domain to complex" mean in terms of Maxima's settings?

Maxima's solve seems to compute complex solutions by default:

(%i21) solve(x^2 + 1);
(%o21)                        [x = - %i, x = %i]

On Sun, 3 Dec 2023 at 13:37, Dima Pasechnik <dimp...@gmail.com> wrote:
>
> Yes, Sage modifies the defaults of Maxima, in particular we set domain to 
> complex.
>
> On 3 December 2023 12:28:45 GMT, Oscar Benjamin <oscar.j.benja...@gmail.com> 
> wrote:
> >On Wed, 29 Nov 2023 at 12:40, Eric Gourgoulhon <egourgoul...@gmail.com> 
> >wrote:
> >>
> >> Le mardi 28 novembre 2023 à 18:25:04 UTC+1, kcrisman a écrit :
> >>
> >> Yes.  Maxima's attitude is that the square root of negative one is an 
> >> expression which might have multiple values, rather than just picking one 
> >> you hope might be consistent over branch points.
> >>
> >> To enforce Maxima to work in the real domain, avoiding to play too much 
> >> with complex square roots, one can add at the beginning of the Sage 
> >> session:
> >>
> >> maxima_calculus.eval("domain: real;")
> >>
> >> Then the second example in the initial message of this thread yields
> >>
> >> [[x == 2/5*sqrt(6)*sqrt(5), y == 16, l == 1/9*18750^(1/6)], [x == 
> >> -2/5*sqrt(6)*sqrt(5), y == 16, l == -1/9*18750^(1/6)]]
> >>
> >> instead of an empty list.
> >
> >When using Maxima (5.45.1) directly I get this result with default settings:
> >
> >(%i1) f: 10*x^(1/3)*y^(2/3)$
> >
> >(%i2) g: 5*x^2 + 6*y$
> >
> >(%i3) solve([diff(f,x)=l*diff(g,x), diff(f,y)=l*diff(g,y), g=120], [x,y,l]);
> >                                        1/6
> >            2 sqrt(6)              18750
> >(%o3) [[x = ---------, y = 16, l = --------],
> >             sqrt(5)                  9
> >                                                                          1/6
> >                                            2 sqrt(6)                18750
> >                                     [x = - ---------, y = 16, l = - 
> > --------]]
> >                                             sqrt(5)                    9
> >
> >Does Sage modify some Maxima settings related to this or does it call
> >something other than solve?
> >
> >--
> >Oscar
> >
>
> --
> 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/6F4839F2-38B6-40F2-B080-EFCC1C0C3B65%40gmail.com.

-- 
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/CAHVvXxQpSk-UpbgHEZ0dVaPFRcZ79SV0_vgC1Y%3DdGM_32T2KgA%40mail.gmail.com.

Reply via email to