10 Secret Trig Functions Your Math Teachers Never Taught YouHaversine?
Exsecant?
An introduction to obsolete trig functions and why we don’t use them anymore
Scientific American Blog NetworkEvelyn Lamb
[https://blogs.scientificamerican.com/roots-of-unity/10-secret-trig-functions-your-math-teachers-never-taught-you/]
Excerpt from
https://blogs.scientificamerican.com/roots-of-unity/10-secret-trig-functions-your-math-teachers-never-taught-you/