IMHO there ought to be possible to return "Unknown" as the result. Indeed, in many cases such an exact computation is not feasible.
On Saturday, January 7, 2017 at 9:54:36 PM UTC, vdelecroix wrote: > > Hello, > > Some symbolic expressions claim that they are not real > > sage: cos(pi/7).is_real() > False > sage: (exp(I*pi/7) + exp(-I*pi/7)).is_real() > False > > But conversion to real floating points perfectly works > > sage: RR(cos(pi/7)) > 0.900968867902419 > sage: RR(exp(I*pi/7) + exp(-I*pi/7)) > 1.80193773580484 > > I guess we could (and should) make it consistent. See also the related > #16436. > > Vincent > -- 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.
