## Friday, November 2, 2012

### Intro to Waves...?

I am just going to try introducing waves like this this year in Grade 11. I hope it doesn't suck.

PS. They've "seen" sine and cosine functions before in Grade 10. Else I don't think you can introduce it this way and expect them to associate it with sine and cosine automagically. So I guess the proper title of this post would have been "Re-Intro to Waves...?"

#### 1 comment:

1. Isn't it weird that moving around a circle produces a wave-shaped function graph? I mean, of course it's not weird to US, but to students? I think the most successful way I've found of introducing these functions is by first working a lot with trig ratios on the unit circle (which entails a lot of discussion about negative trig ratio values, obtuse triangles, etc), having students construct a table of values of these ratios using the unit circle and rulers/protractors (no calculator), and then graphing those values as points in a coordinate system. Then we discuss over and over WHY the functions look like waves, why the period is 360, amplitude is 1, etc, and how these would change using a different circle. This decontextualized approach works well with SL and HL, but Studies doesn't have obtuse triangles or unit circle in their syllabus, so with them I'm still stuck.