behavior of asec()

[Bruce Allen]

Dear Sympy developers,

This is not a serious issue, but I wanted to flag it. According to the
documentation (and IMO correctly):

acos(x) = asec(1/x)

So I was surprised to see the contrast between:

>>> acos(Rational(1,2))
pi/3

>>> asec(Rational(2,1))
asec(2)

I would expect the previous line to return pi/3. Here is another
example of this:

>>> acos(sqrt(2)/2)
pi/4

>>> asec(2/sqrt(2))
asec(sqrt(2))

I would expect the previous line to return pi/4.

Cheers,
Bruce

[Aaron Meurer]

What version of SymPy are you using? Those both evaluate for me as
expected in 1.7.1.

Aaron Meurer

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[B A]

My previous message can be ignored -- as Aaron pointed out (thank you!) this has been fixed, I was not using a recent-enough release.  Sorry for the noise.

Python 3.9.2 (default, Mar 31 2021, 11:25:52) 

[Clang 10.0.1 (clang-1001.0.46.4)] on darwin

Type "help", "copyright", "credits" or "license" for more information.

>>> import sympy

>>> from sympy import asec, Rational, acos

>>> sympy.__version__

'1.7.1'

>>> acos(Rational(1,2))

pi/3

>>> asec(Rational(2,1))

pi/3