# Trig function names: math history?

Homework Helper
Does anyone know how the function names sin, cos, csc, sec, ... came about?

Wouldn't they be easier to remember if cos was 1/sin; csc was 1/sec; just like cot is 1/tan? (Instead of 1/sin = csc and 1/cos = sec.)

This is one thing in trig that always throws me off.

TenaliRaman
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Trigonometric_functions.html

Note that these notations came out of necessity (for simplification) and not through a magic wand

-- AI