Discrete Mathematics

Math 245
Fall 2003
Schedule Number: 21044
Meeting: MWF, 12:00-12:50.
SS 1401
San Diego State University

Professor: Mike O'Sullivan
Email: m.osullivan@math.sdsu.edu
Office: GMCS #579, ext. 594-6697
Office Hours: MWF: 10:00-11:30, MWF 1:00-1:45.
                              Other times: by appointment.


S. Epp, Discrete Mathematics with Applications, 2nd Ed.

Detailed Information

REVIEW SHEETS:    First Exam,    Second Exam,    Third Exam,    Final Exam.
PRACTICE TESTS:    First Exam,    Second Exam,   

Course Description

Discrete mathematics is an exciting and rapidly growing area of mathematics which has important applications in computer science and in many high technology areas. For example, "secure" internet communication, efficient storage of data (e.g. jpeg) and robust communication networks are developed using techniques from discrete mathematics.

This course serves two main populations, students from mathematics and students from computer science. The course also has two distinct goals. One is to teach the basics of set theory, logic, combinatorics and graph theory. The other is to convey the rigorous use of terminology and proof which is essential to mathematics: that is, clarity and precision in definitions and statements of fact, and logical methods for establishing that a statement is true. The fundamental mathematics taught in this course is useful in computer science, electrical engineering. The analytical skills developed are critical to understanding computer languages, to the development of good programming skills, and, more generally, to appreciating scientific method. The experience with abstract concepts, proof writing and the use of formal definitions should help students in all disciplines to articulate their ideas more clearly.


Here is a rough idea of the amount of time I expect to spend on each topic, and the order in which we will cover them. I am also open to suggestions if the class would like to spend more time on certain topics or cover items not listed here. A day by day schedule (see above) will be maintained to keep you informed of upcoming and past lectures.

§1.1-4 Logic and logical arguments. 4 classes
§2.1-3 Predicates and quantifiers. 4 classes
§3.1-7 Proof: direct proof, division into cases,proof by contraposition,
proof by contradiction and disproof by counterexample.
6 classes
Some number theory: Statements of the division theorem, unique factorization.
Proof of the irrationality of sqrt(2), proof of the infinitude of primes.
§5.1-3 Sets: subsets, union, intersection. 4 classes
Venn diagrams. Algebra of set operations.
Cartesian product, power set.
§10.1-3,5 Relations. Reflexive, symmetric and transitive relations. 6 classes
Equivalence relations. Partially ordered sets
§7.1,3,4,5 Functions: one-to-one and onto functions. 4 classes
Invertible functions. The pigeonhole principle.
Composition of functions.
§4.1-4 Sequences, mathematical induction 4 classes
§8.1-3 Recursively defined sequences: 4 classes
Finding explicit formulas,
establishing the formulas by induction.
§6.1-7 Combinatorics: Counting and the multiplication rule. 6 classes
Permutations and combinations.


We will have weekly assignments, three midterms and a final exam. For the weekly assignments (see above), there will be a small number of problems (10 or so) which you should write up carefully. They will be graded and returned to you promptly (to the best of my ability).

Most students find this a tough class. You will greatly magnify your chances of succeeding if you work regularly and attentively! Start the assignments early and do most of the exercises in each section we cover. If you get stuck, please ask me in class. Your questions often lead to a valuable class discussion. You are also quite welcome during my office hours, but come prepared.

Point value for the work will be as follows (plus or minus 50 points)
Weekly work 200
Test 1 150
Test 2 150
Test 3 150
Final 350
Total 1000

The first exam is tentatively Mon. 10/6.

The second exam is tentatively Wed 11/3.

The third exam is tentatively Mon. Nov 24.

The final exam is Wednesday, Dec. 17, 10:30-12:30.