Constructing Trig Functions with Sketchpad

I reviewed graphing Trig Functions today in Calculus.

First I show show student the segment(red) that is represented when we use the word sine.

I drag it around the circle so that they can see how it changes. They note anything that they notice about it. (it doesn’t get any longer than one, etc…)

Then we look more specifically at many lengths and how they would be graphed. Then I graph it with sketchpad.

As I slowly change the angle we can see the sine length at each angle represented on the x-axis.

I then went through and did this for each of the trig functions. I had students follow along creating a foldable (my first foldable ever). I added a sample on the bottom.(scroll down)

I’ve attached my sketchpad file below. Feel free to use it and/or improve it.

In order to view the file, Constructing Trig Functions, you need to download Geometer’s Sketchpad. For viewing/interacting purposes you can just use the free trial version.