Give Your Simple Trigonometry problems a (sin) Wave Goodbye

Kate Nowak: mild mannered high school math teacher, or genius extrordinaire? You decide (I hate suspense: she's both).

As I've been bludgeoning my way through calculus, I've been discovering that trigonometry (or as students refer to it: flippin' ghey math) is becoming more and more important. While googling trigonometric mnemonic devices this evening, my buddy Max came across this gem in the rough on Kate's blog f(t):



I won't paraphrase her description since she pretty much nailed it, so let's use some quotes...

"Flip down the finger that corresponds to the angle whose sine and cosine you need.
The number of fingers to the left gives you the sine, and the number of fingers to the right gives you the cosine.

So if you flip down your index finger which corresponds to 30 degrees...
there is one finger to the left.
and there are three fingers to the right.

Try it for the fingers that correspond to the other reference angles. For example, if you flip down your pinky, there are four fingers to the left (sin(90) = radical 4 over 2 = 1) and zero fingers to the right (cos 90 = radical 0 over 2 = 0.) It works!

It's just another way of organizing the cofunction behavior of sine and cosine to remember the values of five reference angles, but adults and kids both flip out when I show them. Kids especially feel that they "don't have to memorize" if they know this method."

Hey Gents, I don't see a ring on that left hand. Hats off to Kate, trigonometry superhero.