Fermat’s Last Theorem began with an equation a student can understand and ended in a proof joining number theory, ideals, elliptic curves, modular forms, Galois representations, and Taylor–Wiles patching. This visual master lesson develops the 358-year history, the complete contradiction architecture, verified worked examples, and the precise relationship to modern elliptic-curve cryptography.
Prime numbers are the multiplicative building blocks of the integers. In this Woody Calculus lesson, learn the formal definition of a prime, why 1 is excluded, the Fundamental Theorem of Arithmetic, Euclid’s proof of infinitely many primes, the Sieve of Eratosthenes, prime patterns modulo 6, the Prime Number Theorem, modern cryptography, and the deep connection between primes and the Riemann Hypothesis.
![Ideals and quotient rings Abstract Algebra infographic comparing Z/5Z with Q[x]/(x^2-2) to show how collapsing an ideal to zero creates a new algebraic structure.](https://k3p6r8v3.delivery.rocketcdn.me/wp-content/uploads/2026/08/Ideals-and-Quotient-Rings-Slide-1.png)
This lesson explains ideals and quotient rings in a clear, visual way. Learn what an ideal is, how quotient rings are formed, why prime ideals correspond to integral domains, why maximal ideals correspond to fields, and how irreducible polynomials in F[x] create new field extensions.
Polynomial irreducibility is never just about the polynomial—it depends on the coefficient ring or field. Learn a complete Abstract Algebra decision system using root tests, the Rational Root Theorem, Gauss’s Lemma, Eisenstein’s Criterion, reduction modulo p, finite-field factor tests, quotient rings, and field extensions.
Learn group homomorphisms through visual intuition, exact definitions, complete proofs, and a detailed map from the integers to Z₄. This Woody Calculus lesson explains operation preservation, kernels, images, fibers, quotient groups, injectivity, surjectivity, and the First Isomorphism Theorem.
A group is a set with a binary operation satisfying closure, associativity, identity, and inverse axioms. Learn these four axioms through Z4, Cayley tables, element orders, generators, cyclic groups, and the symmetries of an equilateral triangle.
The Frobenius automorphism \(x\mapsto x^p\) is the central symmetry of finite fields. This Woody Calculus Abstract Algebra lesson explains characteristic \(p\), the Freshman’s Dream, cyclic finite-field Galois groups, Frobenius conjugates, trace, norm, unit circles, and how these ideas connect to modern finite-field research.
Why does the simple cubic x³ − 2 create the six-element symmetry group S₃? This Woody Calculus Abstract Algebra lesson explains the roots, splitting field, extension degree, automorphisms, triangle symmetries, and quotient group connection behind one of the cleanest examples in Galois theory.
Field extensions are how Abstract Algebra builds a bigger number system when a polynomial has missing roots. In this Woody Calculus visual lesson, learn how Q becomes Q(√2), why x² − 2 has no rational root, how degree and minimal polynomials work, and why field extensions open the door to Galois theory.
Quotient groups are how Abstract Algebra collapses a group into a simpler structure. In this Woody Calculus visual lesson, learn how cosets become the new elements, why normal subgroups are required, how modular arithmetic is a quotient group, and how kernels lead directly to the First Isomorphism Theorem.