Well... Sage does not, indeed, "automagically" apply all possible trig identities <http://www2.clarku.edu/faculty/djoyce/trig/identities.html>. But perusing them allow to select (with a tiny grain of salt) the right one:
sage: tan(1/2*arctan(12/5)).subs(tan(w0/2)==sin(w0)/(1+cos(w0))) 2/3 HTH, Le mercredi 20 février 2019 09:15:59 UTC+1, Michael Beeson a écrit : > > sage: t > > tan(1/2*arctan(12/5)) > > sage: t.trig_simplify() > > sin(1/2*arctan(12/5))/cos(1/2*arctan(12/5)) > > sage: n(t) > > 0.666666666666667 > > > But trig_simplify couldn't get 2/3. Maybe there > > is a fancier command that will do it? > > > -- 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.
