Introduction to Combinatorics

Welcome to Math 28! This webpage will be home to the syllabus, homework assignments, and announcements.

Math 28 is a course in combinatorial mathematics. Combinatorics is a branch of mathematics that studies sets (usually finite) of objects that satisfy some properties. In particular, it is concerned with "counting" the objects in a set (enumerative combinatorics), with determining when an object with a required list of properties exist, with constructing and analyzing objects meeting certain properties (as in combinatorial designs and matroid theory), with finding "largest", "smallest", or "optimal" objects (extremal combinatorics and combinatorial optimization), and with finding algebraic structures these objects may have (algebraic combinatorics).

The class meets MWF 12:30-1:35 (12 hour), Haldeman 028. X-hour is Tuesday 1-1:50. We will certainly use X-hour the week of January 21st, to replace the Martin Luther King Day lecture; we will use it elsewhen as needed, but sparingly. Our textbook is the course notes *Combinatorics Through Guided Discovery* by Ken Bogart, available at the Copy Center.

Your instructor is Rebecca Weber (yours truly), and my office is Kemeny 317, phone number 646-1720. It's usually more reliable to email than to call, however. My office hours are Mondays 4-5, Wednesdays 2-3, Thursdays 1-2, and by appointment.

Here is the syllabus that was handed out.

Tips on writing proofs (2-page pdf).

If you want to learn the LaTeX typesetting system for writing up homework (highly recommended), I have a page of resources.

Help on Material

There are many ways to get help with the material. Here are some:

- Ask questions during, before, or after class.
- Discuss material with your classmates. I want everyone to write up their own homework, but feel free to discuss it with each other.
- Come to office hours to discuss questions. Office hours are nothing more than time put aside when I am guaranteed to be in my office free to meet with you. You do not need to make an appointment, nor feel bad about interrupting whatever I'm filling my time with when you come in.
- Make an appointment to meet with me. While I prefer this be done only in cases where the above options simply don't work out, or when the discussion is to be confidential, I am happy to meet with you at other times.

Last modified December 30, 2007