Unit Circle Practice

Sam Shah's applet for practicing finding special angles on the unit circle and their sines and cosines

Square Pyramid: Underlying Anatomy

From Tim Brezinski

Domain of a Function defined by a Composition

I created this GeoGebra

applet to help with visualization of the domain of a function defined by a composition.

Euclid's Algorithm

This tool for visualizing of Euclid's algorithm (programmed by Jason Davies) comes from Underground Mathematics. Fawn Nguyen has written a fabulous narrative on how she used it as a notice-and-wonder activity with her sixth graders. What she did would work just as well with high school students. All you need to get started are two positive whole numbers.

Snail's Trail Quilt Square

I created this GeoGebra applet based on a quilt square pattern to use in a precalculus class as a visual introduction to the sum of an infinite geometric series. A nice accompaniment is this applet from Irina Boyadzhiev. I also created a Desmos activity with a focus on asking questions which incorporates these two applets.

Visualizing radians

Sam Shah shared a GeoGebra applet created by a colleage of his which does a beautiful job of demonstrating what a radian is. He wrote about it here. I made minor modifications, mostly so that the word radian doesn't actually appear. Here's that slightly modified version.

Exponential Models Card Sort

Thanks to the ever-innovative-and-tuned-in-to-what-teachers-would-love-to-have Desmos team, I've created an online version of a card sort that I originally developed in paper form to help precalculus students think carefully about the meaning of the parameters in various forms of exponential equations. See this blog post for more detail on the context in which I use this.