Math 120: Groups and Rings (Spring 2023)

This class will meet MWF from 9:30-10:20 in 380W

The text will be Dummit and Foote Abstract Algebra, Third edition. We will cover group theory (through the Sylow theorems), and beginning ring theory. Although groups are more "basic" algebraic objects, rings are also pervasive and useful even in thinking about groups. I will talk about rings from an early stage, and I recommend that you read Section 7.1 in the book early.

Office hours

There will be two gradesccope midterms in weeks 4 and 8, a writing project due in week 6, and a final. This policy may change but I'll confirm a definite timetable in a few days.

Midterm 1

Midterm 1 will be a Gradescope midterm, to be taken either Thursday March 28, Friday March 29 or Saturday March 30 before Noon when the Gradescope closes for this exam. Budget 1 hour 20 minutes. It will cover Dummit and Foote, through Section 3.2. It will be open book in that you may consult Dummit and Foote, but no other sources.

Writing Mathematics

The Writing in the Major (WIM) project was released Saturday, April 29, and will be due Tuesday, May 9. Before you start it, I would like you to read the following materials.

You are strongly encouraged to use latex for the WIM project.

In case you have not learned latex, here is a short document to help get you started. There is more in the appendix to Writing Mathematics.

WIM project

The WIM project is available on Gradescope, due May 9. For your convenience, here is a copy of the pdf filed describing the project.

Announcements for Week 5

We are starting Chapter 4, and will move as quickly as we can to the Sylow Theorems. Please start reading Chapter 4 if you haven't done so already.

Homework

Homeworks will usually be due on Tuesdays in Gradescope.

HomeworkDummit and FooteSolutions
HW1 (due Tuesday April 11, 2023)
Section 1.1 #6,12,15,22,25;
Section 1.2 # 1,2,3;
Section 7.1 # 3,5.
HW1 Solutions
HW2 (due Tuesday April 18, 2023)
Section 1.2 #9;
Section 1.3 #2 ($\sigma,\tau,\sigma\tau,\tau\sigma$ only), 5,13,20;
Section 1.4 #7, 1.5 #2, 1.6 #1
HW2 Solutions
HW3 (due Tuesday April 25, 2023)
Section 1.7 #11, 17, 19;
Section 2.2 #7, 10;
Section 2.3 #17, 25;
Section 3.1 #9, 32, 33;
HW3 Solutions
HW4 (due Tuesday May 2, 2023)
Section 3.1 #34, 36, 42;
Section 3.2 #8;
Section 3.3 #2 (Prove bijection and statement (1) only), 3;
Section 3.5 #1, 7;
HW4 Solutions
WIM project (due May 9)See above
HW5 (due Tuesday May 16, 2023)
Section 4.1 #1
Section 4.2 #2,9
Section 4.3 #4,22
Section 7.3 #25,26,34
For #34, assume $R$ has an identity $1\in R$
HW5 Solutions
HW6 (due Tuesday May 23, 2023)
Section 4.3 #28,34
Section 4.4 #2,13
Section 4.5 #13,25
Section 7.4 #37
Section 7.5 #3
HW6 Solutions
HW7 (Tuesday May 30, 2023)
This will not be collected
Section 5.4 #12
Section 5.5 #7,8
Section 8.2 #1,4,8
Section 8.3 #2
HW7 Solutions