Directional Derivative and Gradient Vector - Calculus 3

This video explains the directional derivative, including the limit definition, its relation to the partial derivative, gradient vector (how it gives the direction of the maximum rate of increase of a function and its orthogonality to level curves), extension to functions of three variables, and worked example practice problems.

0:00 Directional derivative, limit definition
4:21 Gradient vector
12:44 Gradient and Level Curves
18:42 Directional derivative, functions of three variables
20:52 Worked examples