Calc students are making deep observations in a marbleslides activity that I made at @Desmos HQ last summer. Type in the equation of a function to collect stars with its *derivative*. Full activity here:
https://teacher.desmos.com/activitybuilder/custom/5d2b8d2d966a7f27cd7927d4Screen
https://teacher.desmos.com/activitybuilder/custom/5d2b8d2d966a7f27cd7927d4Screen
There appears to be an issue with the link. Here's another attempt. Sorry! https://teacher.desmos.com/activitybuilder/custom/5d2b8d2d966a7f27cd7927d4