Explore the intricacies of partial derivatives in this comprehensive 3.5-hour lecture series. Delve into topics such as polar and spherical limits, the chain rule, Clairaut's theorem, implicit differentiation, tangent planes, and linear approximations. Master practical applications including surface area and volume optimization, the second derivative test, and Lagrange multipliers. Gain a deeper understanding of calculus concepts like the arithmetic-geometric mean inequality and distance calculations between points and planes.