4-3 The Second Fundamental Theorem, Rate Graphs, Average Value of a Function

I split this section into its three distinct parts(3 different videos).

1) 4-3 Part I- FTC #2

2) Interpreting Rate Graphs

3) Average Value of a function.

Below is a great video from 3Blue1Brown, which summarizes many concepts of integrals so far. Thanks Zhirou for the share!