Read the first two paragraphs from the "On the Role of Sign Charts" document, which is duplicated below for your convenience.

That last sentence references 1987 AB4 (a). Consider the video below to be your appendix, complete with an historical footnote. Duration: 10:35

Again in the "On the Role of Sign Charts" document, read the paragraph under 2. Local Extrema, The Second Derivative Test.

Now let's work through 2002 Form B (whatever that is) AB5/BC5 (a). Duration: 12:16

In "On the Role of Sign Charts," read, if you please, the first paragraph under 3. Absolute Extrema.

Understand that we won't be able to complete 2001 AB3/BC3 in its entirety, since it requires Integral Calculus, but at least we can get exposure to how an AP reader expects us to justify our answer when using the Closed Interval test. (I mean, Ethan could probably finish it off, but the rest of us will have to wait until the next unit.) Duration: 6:34

Ethan, since you did such a marvelous job on that last question, could you please read the second paragraph under 3. Absolute Extrema? Everyone else, listen carefully.

In order to understand the technique required to justify the extrema from 1998 AB2 (b), allow me to first demonstrate it on an Algebra 1-Level question. Duration: 15:48