My book will no doubt be flawed in many ways of which I am not yet aware, but there is one “sin” that I have intentionally committed, and for which I shall not repent: many of the arguments are not rigorous, at least as they stand. This is a serious crime if one believes that our mathematical theories are merely elaborate metal constructs, precariously hoisted aloft. Then rigor becomes the nerve-racking balancing act that prevents the entire structure from crashing down around us. But suppose one believes, as I do, that our mathematical theories are attempting to capture aspects of a robust Platonic world that is not of our making. I would the contend that an initial lack of rigor is a small price to pay if it allows the reader to see into this world more directly and pleasurably than would otherwise be possible.
—Tristan Needham, Visual Complex Analysis xi
combinatorics
- it’s time to party (intro motivational problems)
- counting: orderly versus disorderly
- combinatorics to polynomials segue
- some miscellaneous example problems with binomial expansions, etc.
algebraic synæsthesia
- parent functions and their linear transformations
- Polynomials (and sketching them!)
- some fun factoring problems, as review
- Persuading Parabolas into Vertex Form (completing the square as a path to enlightenment)
- Perfecting our Perception of Parabolas (writing assignment to derive some cool parabola theorems) and related: Andrew’s favorite mathematical writing tip
- calculus-free cubic optimization!
- Taylor’s Theorem (Math 3 version) (what if we had infinitely-long polynomials?!?)
- Finding the roots of all polynomials (the linear, quadratic, and cubic formulas, and a soupçon of what’s beyond!)
- the QUARTIC formula!!!! (formulas calculated by Sage and typeset by \(\LaTeX\) in a tiniest-font 72-inch wide PDF)
- Rational functions (what if we could divide polynomials?)
- Blowing up fractions! (a fun algebraic technique, more blandly known as partial fraction decomposition)
- some fun rational function sketching problems
logarithms
- The World Made From Modular Machines (notes on inverse functions, as a primer)
- exponent rules reference sheet (svg)
- fun intro exploratory logs problems
- Logarithms! (intro lengthy exposition and proofs of some basic properties)
- Andrew’s online visual logarithms calculator/pun
- LOGPOCALYPSE
- logpocalype redux (solution notes and further problems)
- tricky quadratic logarithms problem (and solution)
- log base play (and solution notes)
trig
- Radians
- printable fun-fun radians reference poster: svg, pdf
- some example radians to-and-from degrees conversions
- printable fun-fun right-triangle trig functions reference poster: svg, pdf
- Trig Functions, Turbocharged (the unit circle definition of trig functions)
- printable fun-fun unit circle trig functions reference poster: svg, pdf
- some example unit circle-based calculations
- the pythagorean theorem (noah schweber’s crayon-on-wall proof)
- trig identities
- trig equations
- trig word problems
- the super-pythagorean theorem: inducement, notes
- Sum and difference identities: Part I, Part II
- Write Your Own Word Problem
complex nummies
- Numbers, Complicated (introductory notes on complex numbers)
- Let’s multiply things by \(i\)! (exploratory problems)
- Multiplication by \(i\) as rotation
- Complex roots, in a Cartesian sense (project to figure out the cubic/quartic roots of \(i\) in rectangular)
- When It’s \(64\) (short fun problem to compute all of the six sixth roots of \(64\) in rectangular) (solution notes)
- Let’s draw powers of \(i\) and stuff! (exploratory problems to motivate polar coordinates)
- Circumpolar Navigation (notes on polar coordinates)
- Polar Tetris (Andrew’s circular version of Tetris)
- Hilariously Hideous Complex Fractions (fun small exploratory problem involving iterated complex fractions)
- Exponential Improvements (notes on the exponential form and Euler’s Identity)
- \(\sqrt{\text{Complex!}}\) (exploratory problems to figure out complex roots)
- Numbers, Spinning and Unspinning (notes on complex roots)
- ComplexComplexComplex… (notes on complex exponentiation) (also available in zine form)
- Cole’s Conjecture and Maya’s Musing (solution notes)
- Prime numbers aren’t prime (exploratory problems on Gaussian integers)
sequences and serieseses
- sequences and series cold open
- sequences and series basic vocabulary and some fun problems
- A Whole Party of Infinite Friends (some very fun very diverse exploratory intro series problems):
- does \(1/n^2\) converge?
- when does \(n^p\) converge?
calculus!!!
- In the Beginning Was The Derivative
- the derivative of \(x^n\)
- Dffrntn Shrtcts (differentiation laws)
- trig derivatives (statements, not proofs)
- Oh shoot, we need a more rigorous understanding of limits!
- okay, now we can actually prove that the derivative of sine is cosine!
- differentiating logs and exponentials
- what’s the derivative of inverse tangent?
- (Implicit) Differentiation
- Related rates
- Optimization
- Integration
- Some totally unremarkable problems with integrals (exploratory problems)
- Integrals as net area
- Antiderivatives (just… several hundred antiderivative problems!)
- Putting Humpty-Dumpty Back Together (undoing the chain rule)
- Undoing the product rule (integration by parts )
- Integration by parts: some fun examples
- Integrating By Parts By Parts By Parts By Parts… (iterated integration by parts)
- infinite integrals (people call these “improper integrals,” which is silly)
- taylor series intro!
- taylor series derivation!
- taylor series, more algorithmically
- but sometimes you can only polynomialize functions over finite ranges
- can we think about the error term?
- how long are curvy lines?
- higher integrals