Here is some to-my-opinion strange behaviour of trig_expand : #Declare real variables var('a b c') assume([a,'real'],[b,'real'],[c,'real']) assumptions() ---> [a is real, b is real, c is real]
#Case 1 sin(a+b).trig_expand() ---> sin(a)*cos(b) + sin(b)*cos(a) #Case 2 sin((a+b)/2).trig_expand() ---> sin(1/2*a)*cos(1/2*b) + sin(1/2*b)*cos(1/2*a) #Case 3 sin((a+b)/c).trig_expand() ---> sin((a + b)/c) #Case 4 sin((a/c+b/c)).trig_expand() ________ In case 3, the expansion is not done. I wonder if it would be possible to do it. Obviously, if the sine argument was rational expanded before trig expansion, it would work but none seem to work on the whole expression. Any idea ? PS: I am actually using this in an expression where doing this expansion would simplify a lot and I would have expected simplify_full to see it... which it does not, I suspect because of this. ---> sin(a/c)*cos(b/c) + sin(b/c)*cos(a/c) -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org