Gudermannian

== English == === Alternative forms === gudermannian gd (abbreviation) === Etymology === Named after Christoph Gudermann (1798–1852), +‎ -ian. === Noun === Gudermannian (plural Gudermannians) (mathematics) A particular function, g d ( x ) = 2 tan − 1 ⁡ e x − π 2 {\displaystyle \mathrm {gd} (x)=2\tan ^{-1}e^{x}-{\frac {\pi }{2}}} . ==== Further reading ==== Gudermannian on Wikipedia.Wikipedia