To introduce sinusoidal functions, I use an animation of a Ferris wheel rotating for 60 seconds, with one seat labeled You (see fig. 1). Students draw a graph of their height above ground as a function of time with appropriate units and scales on both axes. Next a volunteer shares his or her graph. I then ask someone to share a different graph. I choose one student with a curved graph (see fig. 2a) and another with a piece-wise linear (sawtooth) graph (see fig. 2b).
Wayne Nirode, email@example.com, teaches mathematics content courses for in-service and preservice teachers at Miami University in Oxford, Ohio. He taught mathematics and economics for twenty years at Troy High School in Troy, Ohio. His interests include geometry, statistics, and technology.