As I work with students to analyze graphs, I’ve noticed that many of them have trouble distinguishing whether a function is symmetric about the y-axis or the origin.
I designed this activity to animate the reflection of a function about the y-axis and the rotation of a function about the origin. I chose to illustrate symmetry about the origin as a 180° rotation rather than a reflection through the point (0,0). I think this is easier for the students to learn to visualize in their minds.
To rotate the curve, I defined the rotation using parametric equations. Desmos has a great learning demo on parametrics here
Here’s my activity:
Feel free to duplicate it and try editing it to something useful for your classes! (Remember, if you just click preview, you won’t be able to see anything in a hidden folder. You’ll see it just like the kids will.)