Calculus - Fermat's Theorem (Stationary Points): Explanation and Proof
Channel: Aaron Budke
Date: 2020-05-11

PROOF STEP MISSED: At 5m 56s when we found f(x) - f(c)/x-c is smaller than or equal to zero, you must once again take the limit of both sides as x → c but this time from the positive side (x → c+). Then continue with the proof as in the video.

We will learn about the formal definition for Fermat's Theorem of stationary points, gain an intuitive understanding for the theorem and finally derive a proof for Fermat's Theorem.

0:00 - Formal definition
0:52 - Intuitive understanding
2:16 - Derivatives first principles recap
3:44 - Proof
6:58 - Outro