Second Derivative Animation
Read about derivatives and second derivatives,
if you don't already know what they are!
Here you can see the derivative f'(x) and the second derivative f''(x) of some common functions.
Notice how the slope of each function is the y-value of the derivative plotted below it.
For example, move to where the sin(x) function slope flattens out (slope=0), then see that the derivative graph is at zero. A similar thing happens between f'(x) and f''(x). Try this at different points and other functions.