Gradient, Divergence, and Divergence Theorem

This lecture covers the concepts of gradient, divergence, Laplacian, and the divergence theorem. It explains how to calculate gradients, divergences, and Laplacians in Cartesian coordinates, as well as their applications in scalar and vector fields. The divergence theorem is also discussed, showing how to compute flux through infinitesimal cubes. The instructor, Dr. Sylvain Bréchet, presents theoretical foundations and practical examples to illustrate these fundamental concepts.