Second Derivative Animation

Here we can play with the derivative f'(x) and the second derivative f''(x) of some common functions.

images/function-graph-2deriv.js

Notice how the slope of each graph equals the y-value of the derivative plotted directly below it.

For example, find a point where the slope flattens out (becomes zero), and notice that the derivative graph crosses zero right there too.

A similar thing happens between f'(x) and f''(x). Try this at different points and different functions.

Try these challenges:

  • Find where f(x) reaches a peak or valley: what's f'(x) doing there?
  • Find where f(x) changes its bend (inflection point): what's f''(x) at that exact spot?
  • Pick a straight line function (like 2x + 1): why does f''(x) stay flat at zero?