Yesterday I had passed out a colored sheet of paper and asked my calculus class what topics they want to review as a class and also any suggestions on how we spend our class review time. They were to list a topic, and if their topic was already listed, they were to put a check mark by it, so I could gauge popularity. One of the topics they stressed was derivatives of trig and inverse trig functions.
Today, I listed the 12 trig and inverse trig functions on the overhead and discussed memory tools I had for the derivatives of the 6 trig functions (all the "c" ones are negative; there's always 2 secants and a tangent; cotangent is like the pesky little brother of tangent and wants to be just like him; cosecant ditto to secant). Then I gave them 3 minutes, and they were to come up with memory tools for the inverse trig functions. I didn't know how it was going to work, but there were several good discussions going.
As we met back as a class, the ideas were slow at first, and then I don't know what happened, but as a class they came up with several good ones to remember the derivatives of the inverse trig functions (sin^(-1), cos^(-1), ...):
* if the name has a "t" in it, then there's a "+" (1+xx) which looks like "t"
* if there's an "s" anywhere in the name of the function, it involves a "s"quare root
* anything starting with a "c" has a negative (think grade c-)
* we learn sine and cosine 1st, so those are "1-xx" (as opposed to "xx-1")
Whew! I think those may even help me remember the inverse trig derivatives :).