Le ven. 16 mai 2025, 14:28, Waldek Hebisch <de...@fricas.org> a écrit :
> On Fri, May 16, 2025 at 01:40:55PM +0200, Grégory Vanuxem wrote: > > Hello Waldek, * > > > > Le jeu. 15 mai 2025 à 22:53, Waldek Hebisch <de...@fricas.org> a écrit : > > > > > On Thu, May 15, 2025 at 07:40:39PM +0200, Grégory Vanuxem wrote: > > > > > > > > > > > If you wander why FriCAS leaves asin(sin(x)) unsimplified, this > > > is due to branches, sin(x) = sin(x + 2*%pi), applaying asin > > > to both sides and using unsound transformation of asin(sin(x)) > > > to x would give false equality x = x + 2*%pi. Similarly, > > > pulling %i before square roots leads to nonsense like the last > > > result in the following mail. > > > > > > > The second mail use behind the scene Mathematica (jWSExpression) > > > > I can agree that, in general, branches can interfere but in this case, > > applying the operations used here on -3/2 should return from my point of > > view -3/2. That's just surprising for me. Other CAS returns in fact -3/2 > > and that's correct. > > Yes, in this case it is what you want. Transformation 'asin(sin(x))' > to 'x' was in NAG Axiom, it was blocked later because it may lead to > wrong results. > I guessed that. BTW thanks for your response. Greg -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/fricas-devel/CAHnU2dbBcNgU1rLdaRQk%3DLd-2eqO7F-urh6LWKOw0K2Hv%2Bd8xQ%40mail.gmail.com.
