Many variables, gradients and the geometry of space.
Arrows with length and direction: how to add them, scale them, and multiply them with the dot and cross products.
Lines, planes and surfaces in 3D, functions of several variables, curves traced by vector functions, and the cylindrical and spherical coordinate systems.
Rates of change for functions of several variables: limits in the plane, partial derivatives, the multivariable chain rule, and the gradient.
Tangent planes and linear approximation, critical points of surfaces, absolute extrema on regions, and optimization with constraints.
Integrating over regions and solids: iterated integrals, polar, cylindrical and spherical coordinates, the Jacobian, and surface area.
Vector fields, integrating along curves, the work done by a force, conservative fields, and Green's theorem.
Curl and divergence, parametric surfaces, flux through a surface, and the theorems of Stokes and Gauss that tie it all together.

Level curves and gradients

Absolute extrema on a closed region

Green's theorem

Flux and the divergence theorem

Gradients of scalar fields

Directional derivatives and the gradient

Lagrange multipliers

The multivariable chain rule

Line integrals and conservative fields

Curvature

Partial derivatives

Double integrals

Tangent planes and linear approximation

Quadric surfaces

Green's and Stokes' theorems