simplify_trig and sorting, for example in fractions

simplify_trig

The output of

show((1-cos(x)^2.simplify_trig())
show((cos(x)^2-1).simplify_trig())

sin(x)^2
cos(x)^2-1.

Even worse, the result of

 (sin(x)^2/(1-cos(x)^2)).simplify().simplify_trig()

 -(sin(x)^2/(cos(x)^2-1)

when it should be 1. Is there anyway to get sagemath to simplify trigonometric expressions more intelligently?

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answered 6 years ago

Emmanuel Charpentier
7804 ●8 ●52 ●155

Works for me (Sagemath 8.7):

sage: (cos(x)^2-1).simplify_trig()
-sin(x)^2

similarly :

sage: (sin(x)^2/(1-cos(x)^2)).simplify().simplify_trig()
1
sage: (sin(x)^2/(1-cos(x)^2)).simplify_trig()
1

Note that:

sage: (cos(x)^2-1).trig_reduce()
1/2*cos(2*x) - 1/2

might be more useful...

What are you using ?

link

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I upgraded to sagemath 8.6 (the latest version with binaries available for my system), and this now works. Thanks for pointing out to use newer versions.

my_screen_name ( 6 years ago )

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Asked: 6 years ago

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Last updated: Mar 24 '19

simplify_trig and sorting, for example in fractions savecancel