Mathematical Foundations
Rebuild school mathematics as an adult: algebra as structure, functions and graphs, logarithms, trigonometry, and a first taste of proof.
From counting to the real line
Each kind of number is forced into existence by an equation the previous kind cannot solve, and the chain runs from counting to the continuum.
The rules of algebra
The short list of laws that licence every manipulation, why subtraction and division are not fundamental, and why dividing by zero is barred.
Equations and the quadratic
Solving by inverse operations, deriving the quadratic formula by completing the square, and reading the discriminant before doing any work.
Functions and inverses
The rule that gives one output per input: domain, range, composition, and the condition a rule must meet before it can be run backwards.
The plane and the graph
Coordinates make a function visible: distance, the straight line, the parabola read off its vertex form, and what shifting and stretching do to an equation.
Polynomials and their roots
Degree, division with remainder, the factor theorem, and why the roots of a polynomial and the shape of its graph are the same information twice.
Exponentials and growth
Extending repeated multiplication to every real exponent, the number compound interest converges on, and why every exponential eventually beats every polynomial.
Logarithms
The inverse of the exponential: how it turns multiplication into addition, how it solves for an unknown exponent, and why so many measurement scales are logarithmic.
Trigonometry of the right triangle
Ratios fixed by an angle alone, the exact values worth knowing, and the sine and cosine rules that reach triangles with no right angle in them.
The unit circle and periodic functions
Escaping the triangle: definitions valid for every angle, radians, the wave graphs, and the identities that fall out of the circle.
Sequences and series
Arithmetic and geometric patterns, closed forms for their sums, why an infinite series can have a finite total, and the loans they price.
What a proof is
Direct argument, contrapositive, contradiction and induction, put to work on the two claims this course left open.