A theme this year has been to build in novel activities or situations for my students to deal with other than just give them a handout everyday. Now, I do have plenty of handouts when it's time to put things into practice, but I want at least half our time to be spent doing unique things where I'm not just talking. I also have 1 block day with every class per week and I want to take advantage of the added time other than just "oh I can teach TWO textbook sections today!" So I've expended a lot of energy trying to make "long day" (in kid parlance) a meaningful part of the week. Earlier in the year we made quadratic model videos as an introduction. We did it on long day. I came up with the idea the night before while randomly driving around. Log War was long day. Now, meet Inverse Trig War.

Struggling yet again to find a suitable use for long day, around 9pm while randomly driving around this happened:

@samjshah omg, picture @k8nowak 's log war activity but with inverse unit circle trig

— Jonathan (@ultrarawr) December 5, 2012

And thus, Inverse Trig War was born. I whipped up a list of 40 simple trig equations (things like sin x = 1, 2cos x = 1) and assembled them the same way as the log cards. Now, this game is a little more involved, as determining the value of the card is not as quick. So I had the kids divide up the cards, determine the values as a hivemind like "answer key" and then play. We had been working on Trig Equations earlier in the week and they had struggled with Unit Circle Inverse Trig anyway (especially tangents) so this was some nice reinforcement. Since each card has two angles associated with it, I had them set the "card value" at the highest angle. So if your solutions were 60 and 300, the card is worth 300. You could also play a variant where the lowest value wins.


PreCal kids being the good little soldiers that they are, took the task well. A few groups got invested in the game, some got bored after 10 minutes. But, still interesting and something that might only need minor tweaks. Before I started the games, we did a little collective checking of the answer key just to make sure. They still get weirded out by things like sin x = 1 since normally these things have two answers and a problem like tan x = 1 is solved waaaaaay differently.

Trig War Cards (Word), Trig War Cards (PDF)

AuthorJonathan Claydon