Secret Knowledge

The "Roots of Unity" blog at Scientific American has a post on ten secret trigonometric functions that your math teacher never taught you.

It's interesting, even given that if you judge by my grades, there were some not-so-secret trig functions I never picked up either. Blogger Evelyn Lamb points out that the ten less-common trig functions are various combinations of the basic sine and cosine. While they might be more curiosity than calculation for us today, they served important roles in doing math prior to the invention of good calculators. Logarithmic tables and slide rules used to do the same things -- actually, I guess they would still do the same things, if people used them.

Maybe the best use for the ten "secret" functions today would be as the hook to hang a suspense novel on. By using one of them -- the excosecant, for example, because it sounds cool -- our hero can decode some ancient mystery and prove that Moses looked nothing like Charlton Heston, a secret that the Vatican's clandestine assassination squads will kill to keep. They use poisoned needles in their pectoral crosses, garrotes made from their clerical collars and explosive rosary beads to dispatch their victims.

I bet Dan Brown is working on that book right now.