doctest fix for tan(complex).imag() wrong

[rwst]

sage: tan(2+I).n()
-0.243458201185725 + 1.16673625724092*I
sage: tan(2+I).imag().n()
0.0605381745356926
sage: tan(2+I).imag()
tanh(1)/(tan(2)^2*tan(1)^2 + 1)

There is a form that works at
http://dlmf.nist.gov/4.21.E39

See pynac/pynac#114

Since this is fixed in Sage now, this ticket should provide doctests.

Component: symbolics

Author: Ralf Stephan

Branch/Commit: 7a617e3

Reviewer: Jeroen Demeyer

Issue created by migration from https://trac.sagemath.org/ticket/19791

[rwst]

Changed upstream from Reported upstream. Developers acknowledge bug. to Fixed upstream, in a later stable release.

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comment:1

That bug is in GiNaC too. Fix is in pynac git master, so will be in pynac-0.5.4.

[slel]

comment:2

Fixed by update to Pynac 0.6.0 at #19819?

[rwst]

Description changed:

--- 
+++ 
@@ -12,3 +12,5 @@
 http://dlmf.nist.gov/4.21.E39
 
 See https://github.com/pynac/pynac/issues/114
+
+Since this is fixed in Sage now, this ticket should provide doctests.

[rwst]

Branch: u/rws/tan_complex__imag___wrong

[rwst]

Author: Ralf Stephan

[rwst]

Changed upstream from Fixed upstream, in a later stable release. to none

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New commits:

7a617e3

19791: doctest fix for tan.imag

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Commit: 7a617e3