Study Guide 
Tucker: Applied Combinatorics 
§1.1 Elements of Graph Theory 
Dr. Lee Eimers
Revised 8/31/07
Introduction:  In this section, we begin our study of one of the two main topics of discrete math, that of graph theory.  We meet some of the basic concepts and look at some of the types of problems that can be posed and solved by using graphs. (The other main topic of discrete math is combinatorics, which is the other half of the text and has its own course.)

Concepts and Vocabulary:
The following boldfaced (or italic) terms and phrases introduced in this section.
(* indicates not defined in text)
 
Adjacent vertices 
Bipartite graph 
Chordal graph*
Circuit 
Directed edges Edges 
Graph 
Indifference graph* 
Path
Tree 
Unit-interval graph* 
Vertex basis 
Vertices 
 Points of Interest:

1.  The first couple of pages contain the basic definitions.  The remainder of the section consists of examples, although additional new concepts are introduced in the examples, too, so don't skip over them.

2.  There are some interesting issues related to indifference graphs and preferences.  We will talk about some of them in class.

3.  There are many more examples of uses of graphs found in the problems.  It would be good if you would read through the problems that we don't work just to get a better idea of some of these applications.


 Homework Assignment:
Required Reading:
Chapter 1, Section 1 of text
Bondy and Murty, pp. 1-4;
Diestel, pp. 1-4;
Graph Theory Lessons, Lesson 9: Bipartite Graphs

 Do to hand in: #1, 4, 7, 10, 15, 16, 23, 25, 27 (from text)

Enrichment problems: Anything not previously done in class, but ask me first.  Some of the problems are not really worth counting for enrichment credit.  If you happen to choose to do one of them to work, it will not receive extra credit.


 Thought for the Day
 Definitions:
 College professor: A man who is paid to study sleeping conditions among students.
 College English department: A chamber of commas.
 College education: A form of training which does not hurt you
 provided you study and work hard after graduation.

References:

Graph Theory with Applications, by J. A. Bondy and U. S. R. Murty,
   Online text found at http://www.ecp6.jussieu.fr/pageperso/bondy/books/gtwa/gtwa.html

Graph Theory, 3rd Ed., by R. Diestel,
   Online text found at http://www.math.uni-hamburg.de/home/diestel/books/graph.theory/