sympy/sympy — pull request #7300 by sushant-hiray (2014-03-18 18:58:25+00:00)
Title: Added taylor_term for sec(x)

Added taylor_term for sec(x).
Added unit tests corresponding to it.

Reference terms can be found here[1][2]

[1]https://www.efunda.com/math/taylor_series/trig.cfm
[2]https://en.wikipedia.org/wiki/Taylor_series