In 2013, The Onion thrilled the nation’s math teachers by, at long last, mentioning them:
It’s a headline that bites right to the center of the Tootsie Pop that is our mathematical curriculum. If math is a deafening barrage of arbitrary things to memorize, then trig cranks the volume of gibberish up to 11. I mean, cot2(x) + 1 = csc2(x)? Why do I care again?
Of course, all of trig really just boils down to two functions:
This pair of functions has many offspring, several of which we ask students to learn. Evelyn Lamb lays out some more obscure cousins in a wonderful post:
As Lamb explains, every function in this motley crew once served a useful purpose, back in the days before automated computing. Now, they’re mostly obsolete. So that means we can narrow our attention to the essential few, like sine, cosine, and tangent, right?
Wrong, I say! In the spirit of life imitating The Onion, I propose that all humans memorize the following utterly essential trig functions: