justcalculus
Multivariable calculus notes, slideshows, and explorations
Blog
Can You Bake the Optimal Cake Using Calculus?
Solving FiveThirtyEight's Riddler: maximize the volume of a three-tiered cake that fits inside a cone using multivariable calculus.
Does a Lampshade Cast a Hyperbolic Shadow?
Using parametric plotting and Mathematica to prove that the shadow a lampshade casts on a wall is a pair of hyperbolas.
Modeling the Rolling Shutter Effect
Using Mathematica to simulate how a rolling shutter distorts a spinning propeller, from polar plots to contour plots to animated distortion.
The Riemann Sphere as a Stereographic Projection
Visualizing stereographic projection and the extended complex plane with an interactive Wolfram Demonstration.
Parameterized Families of Elliptic Curves with Large Rational Torsion Subgroups
Exploring one-parameter families of elliptic curves with rational torsion points of order 4 through 12, with an interactive Wolfram Demonstration.
Lecture Notes
13 lessons from parametric plotting through Stokes' Theorem, each available as an interactive slideshow, downloadable PDF, or video lecture.
Lesson 1
Parametric Plotting
Curves, surfaces, solids
Lesson 2
Vectors
Dot products, projection
Lesson 3
Perpendicularity
Planes, cross product
Lesson 3b
Linearization
Tangent planes, mapping
Lesson 4
Gradient Vectors
Level curves, optimization
Lesson 4b
Lagrange Multipliers
Constrained extrema
Lesson 5
Double Integrals
Area, volume, Gauss-Green
Lesson 6
Vector Fields
Flow along and across curves
Lesson 7
Flow Measurements
Path integrals, flux
Lesson 8
Sources, Sinks, Singularities
Green's Theorem, div, curl
Lesson 9
Change of Variables (2D)
Jacobian, polar coordinates
Lesson 10
Change of Variables (3D)
Triple integrals, 3D Jacobian
Lesson 11
Spherical & Cylindrical
Coordinate systems
Lesson 12
Surface Integrals
Flux, Divergence Theorem
Lesson 13
Stokes' Theorem
Curl, 3D path integrals