Wednesday, September 19, 2007

Unit Circle Trigonometry - Follow the White Rabbit

Last class period, my PreCalculus (juniors) and Trigonometry (seniors) built up an understanding of the unit circle through discovery. The basic idea of the activity was, according to one student,
"if you choose one angle, and graph it in each quadrant, then the sin, cos, and tan values are the same in each quadrant, ignoring the plus and minus".

My students were able to work through it with minimal prompting. Through dialogue, students were able to encounter reference angles & triangles and learn the patterns of the unit circle. This and the next pdf are now available on

Today, students completed an arts and crafts activity (they had previously drawn the multiples of 30&45 degree angles on paper plates) by placing the points on the unit circle (all 16 of the 'main' ones).


Students were given the "Follow the White Rabbit" activity. There was a secret message encoded in the Trig and Inverse Trig problems [ "IF I AM A KID, DOES THAT MEAN THAT TRIG IS FOR ME?"]. A few years ago, a student made a poster that morphed the Trix rabbit into a logo for our classroom, "Trig is for Kids", and so I had a scavenger hunt based upon this idea. It was a mixture of Trix, Alice, and Trig.

Here's the progression in the hunt:
  1. Students use trig to decode the message
  2. Students use clues on bottom of worksheet to find an online quiz
  3. Students enter the secret message in the online quiz
  4. Students are given a locker number and combination (to an empty locker)
  5. Students go to the locker, open it, find the Trig Rabbit Poster and a piece of paper with a web address.
  6. Students come back to class, go to the webpage and are given instructions to download a video.
The "prize" at the end is a video of a commercial that a previous student made. In the commercial, I dress up as a bunny. "Silly rabbit, Trig is for kids". It was my first year teaching, and in retrospect, a silly first impression to make on some staff.

Even my most apathetic students were excited and said that they enjoyed the class period. Also, two of my most proficient math students were paired up and, although they finished the trig ratios with little trouble, were some of the last to figure out the rest of the non-math clues.

Students practiced the content, problem solved, and made connections. I want to play more with my students (enhancing mathematics through the play) and this was a great day for both.

1 comment:

Kate said...

Cute! I love scavenger hunts, I'll try to adapt this.

I don't remember where I saw it, but someone posted an example of using three concentric circles instead of your standard reference-angle unit circle. The inner circle had degrees marked, the middle circle radians, and the outer circle had the rectangular coordinates of the points. Less cluttered, at least.