Calculus - Approximate the instantaneous rate of change of a function

In this video I go over how you can approximate the instantaneious rate of change of a function. This is also the same as estimating the slope of a tangent line. You'll see that the key for this is using the average rate of change with two points, and then moving those two points closer together. For more videos check out: http://www.mysecretmathtutor.com