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
