Continuous Everywhere but Differentiable Nowhere

I am teaching exponential functions in my Algebra II classes this week. And I just came back from this teaching conference, where one of the sessions included a few handouts of the types of problems that this one charter school uses. And lucky for me, one was on exponential growth and decay.
I wholesale retyped [...]

I told my calculus class, in the last 15 minutes of class on Monday, that:
“Somebody told me something, and I don’t know if it’s true. They said that if there’s a cubic equation that hits the x-axis three times, then there’s a point of inflection, and it will be the average of these three [...]