Math 71 Algebra


The course textbook Abstract Algebra, 3rd Edition by Dummit and Foote will be referred to by DF.

Weekly problem sets will be due via upload to Canvas by 5 pm on Wednesday.

Weekly Syllabus and Homework

Updated November 13, 2025.

Week Date Topics Reading Homework
1 Tue 16 Sep History of abstract algebra. Some set theory notations. The notion of a group. Examples of groups: modular arithmetic and symmetry groups. Multiplicative group modulo n. Dihedral groups. DF 0.1-0.3, 1.1-1.2
Thu 18 Sep Order of an element and of a group. Symmetric groups. Cycle decomposition. Fields. Matrix groups. DF 1.2-1.4
Fri 19 Sep X-TA Logic, set theory, functions. DF 0.1-0.3
2 Tue 23 Sep Generating set. Presentation. Homomorphisms and isomorphisms. Cyclic groups. DF 1.4-1.6 Problem Set #0
Thu 25 Sep Subgroups. Statement of Lagrange's Theorem. Kernel. Image. Group actions. Examples of group actions. DF 1.7, 2.1-2.2, 4.1-4.2
Fri 26 Sep X-TA Proof writing. Mathematical induction. DF 0.1-0.3
3 Tue 30 Sep Permutation representation. Cayley's Theorem. Orbits. Stabilizers. Conjugation action. Conjugacy classes. DF 4.1-4.3 Problem Set #1
Thu 02 Oct Yom Kippur
Fri 03 Oct X-TA Proof writing. Quiz review.
4 Tue 07 Oct Classification of cyclic groups, and their generators and subgroups. Quiz DF 2.3, 3.1-3.2 Quiz 1 Review

Problem Set #2
Thu 09 Oct Quotient groups via homomorphisms. Quotient groups via cosets. Normal subgroups. Natural projection. Normal subgroups are kernels. Lagrange's theorem. DF 3.1-3.2
Fri 10 Oct Make-up lecture. Homomorphisms from quotient groups. First isomorphism theorem. Third and fourth isomorphism theorems. Lattice of subgroups. DF 2.5, 3.3, 4.1
5 Tue 14 Oct Intersections and joins in the lattice of subgroups. Orbit-stabilizer theorem. Composition series. Jordan-Hölder theorem. Simple groups. Classification of finite simple groups. DF 2.4, 3.4 Problem Set #3
Thu 16 Oct Alternating group. Orbit-stabilizer theorem. Conjugacy classes. Cycle type and conjugacy classes in the symmetric group. DF 3.5, 4.1, 4.2, 4.3
Fri 17 Oct X-TA Midterm exam review.
6 Tue 21 Oct Class equation. A5 is a simple group. Sylow p-subgroup. Sylow's Theorem. DF 4.3, 4.4, 4.5 Midterm Review Sheet
Thu 23 Oct Applications of Sylow's Theorem. Proof of Sylow's Theorems. Groups of order up to 60. DF 4.5
Fri 24 Oct Midterm Exam
7 Tue 28 Oct Fundamental theorem of finitely generated abelian groups. Classification of finite abelian groups. Classification of finite abelian groups. Invariant factors. Elementary divisors. DF 5.1, 5.2 Problem Set #4
Thu 30 Oct Rings. Fields. Division rings. Quaternions. Matrix rings. Group rings. Zero-divisors. Units. Integral domains. DF 7.1-7.2
Fri 31 Oct X-TA More examples of rings.
8 Tue 04 Nov Polynomial rings. Ring homomorphisms. Ideals. Quotient rings. DF 7.1-7.3 Problem Set #5
Thu 06 Nov TA lecturing. Isomophism Theorems for Rings. Simple rings. Principal ideals. Principal ideal domains (PIDs). Z is a PID. Polynomial rings. F[x] is a PID. DF 7.3-7.4, 8.2, 9.1-9.2
Fri 07 Nov X-TA Quiz review.
9 Tue 11 Nov PIDs. Euclidean domains. Euclidean implies PID. Quadratic integer rings. Z[i] is Euclidean. When is a quadratic integer ring Euclidean or a PID? Irreducible and prime elements. Quiz. DF 7.1, 8.1-8.3, 9.1-9.2 Quiz 2 review

Problem Set #6
Thu 13 Nov Unique factorization domains (UFDs). Noetherian rings. Principal ideal domains are unique factorization domains. The fundamental theorem of arithmetic. DF 8.2-8.3, 9.3
Fri 10 Nov X-TA Final exam review.
10 Tue 18 Nov A view of where algebra goes from here. Final Exam Review



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