Mathematics 239 : Introduction to
Mathematical Proof
Fall 2011
Introduction
Professor: Jeff Johannes
Section 1
MWF 10:30 - 11:20a Sturges 105
Office: South
326A
Telephone: 245-5403
Office Hours: Monday 11:30a - 12:20p, Wednesday 4-5p, Thursday 1-2p, 8-9p, Friday 2:30 - 3:30p, and by
appointment or visit
Email Address: Johannes@Geneseo.edu
IM: JohannesOhrs
Web-page:
http://www.geneseo.edu/~johannes
Textbooks
Mathematics: A Discrete Introduction, Second
Edition,
Edward R. Scheinerman
Purposes
- to develop familiarity and comfort with the language of more
formal mathematics and proofs before taking upper division mathematics
coursework
- to learn and justify several techniques for counting
Overview
It is often said that mathematics is a
language. In this class you will begin to learn to speak this
language. Just like in an introductory language course, we will
start with the most fundamental concepts and grammar rules. After
we have some familiarity with the language of formal mathematics, we
will practice this language in the setting of counting problems
of different types. More like an advanced language class,
merely memorizing the vocabulary will not suffice (in fact,
hopefully we can
keep vocabulary to a minimum), but rather you will be required to
understand and speak clearly in this language. The material
learned here will help you understand the mathematics you read and
clarify the mathematics you write. Because we are learning how
to write mathematics, exposition will also be a component in your
evaluation.
Reading
I have intentionally chosen a very readable
text. In addition to planning time to do homework, please take
time to carefully read the sections in the book.
Notice use of the words “time” and “carefully”. Read the sections
slowly. As the author indicates in the preface, read
actively.
If you do not understand some statement reread it, think of some
potential meanings and see if they are consistent, and if all else
fails, ask me. If you do not believe a statement, check it with
your own
examples. Finally, if you understand and believe the statements,
consider how you would convince someone else that they are true, in
other words, how would you prove them?
Because the text is exceptionally accessible, we
will structure classtime more as an interactive discussion of the
reading than lecture. For each class
day there
is an assigned reading. Read the section before coming to
class.
In addition to the reading, there are also indicated exercises to
check that you understood the reading. If there are no questions
from
the reading we will discuss those indicated exercises during the class
discussion.
Grading
Your grade in this course
will be based upon your performance on homework, quizzes and three
exams. The weight assigned to each is designated below:
Homework (6)
5% each
Quizzes (3)
5%
each
Colloquium Report (1) 5%
In-class exams (2)
15% each
Final exam (1)
20%
Homework
There will be homework assigned at the onset of each
new chapter. Homework will be due shortly after each chapter
ends. You are encouraged to consult with me outside of class on
any questions toward completing the homework. You are also
encouraged to work together on homework assignments, but each must
write up their own well-written solutions. A good rule for this
is it is encouraged to speak to each other about the problem, but you
should not read each other's solutions. A violation of this
policy will result in a zero for the entire assignment and reporting to
the Dean of Students for a violation of academic integrity. Each
question will be
counted in the following manner:
0 – missing or plagiarised question
1 – question copied
2 – partial question
3 – completed question (with some solution)
4 – completed question correctly and well-written
Each entire homework set will then be graded on a 90-80-70-60% (decile)
scale. Late items will not be accepted. Homework will be
returned on the following class day along with solutions to the
problems. Please feel free to discuss any homework with me
outside of class or during review.
On the assignments throughout the semester there are
optional items indicated by parenthesis. They may be replaced by
the replacements following them. If all of your problem sets at
the end of the semester are complete (i.e. at least 2 points on each
problem) and you have submitted none of the optional problems, I will
add 11 points to your final problem set score.
Quizzes
There will be short quizzes after the homework has
been returned, covering the material in the chapter from the
homework. For chapters immediately preceding exams, there will be
no quiz. Quizzes will consist of routine questions, and will have
limited opportunity for partial credit. Because quizzes will consist of
routine questions, they will be graded on a decile
scale. There will be no makeup quizzes.
Colloquium Report
Attend one of the department colloquium talks. Write a report.
In the report, describe the content of the talk (including a
detailed discussion of the mathematics). In addition to your
description of the talk, also write how this talk added to your
understanding of the nature of mathematics. Papers are due within
a classweek of the colloquium presentation. I will gladly look at
papers before they are due to provide comments.
Exams
There will be two exams during the semester and a
final exam during finals week. If you must miss an exam, it is
necessary that you contact me before the exam begins. Exams
require that you show ability to solve unfamiliar problems and to
understand and explain mathematical concepts clearly. The bulk of
the exam questions will involve problem solving and written
explanations of mathematical ideas. The final exam will be
half an exam focused on the final two chapters, and half a cumulative
exam. Exams will be graded on a scale approximately (to be
precisely determined by the content of each individual exam) given by
100 – 80% A
79 – 60% B
59 – 40% C
39 – 20% D
below 20% E
For your interpretive convenience, I will also give you an exam grade
converted into the decile scale. The exams will be challenging
and will require thought and creativity. They will not include
filler questions (hence the full usage of the grading scale).
Feedback
Occasionally you will be given
anonymous feedback forms. Please use them to share any thoughts
or concerns for how the course is running. Remember, the sooner
you tell me your concerns, the more I can do about them. I have
also created a web-site
which accepts anonymous comments.
If we have not yet discussed this in class, please encourage me to
create a class code. This site may also be accessed via our course
page on a link entitled anonymous
feedback. Of
course, you are always welcome to approach me outside of class to
discuss these issues as well.
Social Psychology
Wrong answers are important. We as individuals
learn from mistakes, and as a class we learn from mistakes. You
may not enjoy being wrong, but it is valuable to the class as a whole -
and to you personally. We frequently will build correct answers
through a sequence of mistakes. I am more impressed with wrong
answers in class than with correct answers on paper. I may not
say this often, but it is essential and true. Think at all times
- do things for reasons. Your reasons are usually more
interesting than your choices. Be prepared to share your thoughts
and ideas. Perhaps most importantly "No, that's wrong." does not
mean that your comment is not valuable or that you need to censor
yourself. Learn from the experience, and always try again.
Don't give up.
Academic Dishonesty
While working on homework with one another is
encouraged, all write-ups of solutions must be your own. You are
expected to be able to explain any solution you give me if asked.
The
Student Academic Dishonesty Policy and Procedures will be followed
should incidents of academic dishonesty occur.
Disability Accommodations
SUNY Geneseo will make reasonable accommodations for
persons with documented physical, emotional or learning
disabilities. Students should consult with the Director in the
Office of Disability Services (Tabitha Buggie-Hunt, 105D Erwin,
tbuggieh@geneseo.edu) and their individual faculty regarding any needed
accommodations as early as possible in the semester.
Religious Holidays
It is my policy to give students who miss class
because of observance of religious holidays the opportunity to make up
missed work. You are responsible for notifying me no later than
September 12 of plans to observe the holiday.
Schedule (subject to change)
August 29
- September 12 Chapter I reading discussions
September 14 Chapter I homework due
September 19 Chapter I quiz taken
September 14 - 23 Chapter II reading discussions
September 26 Chapter II homework due
September 26 - 28 review Chapters I and II
September 30 In class exam
covering
Chapters I and II
October 3 - 14 Chapter III reading discussions
October 17 Chapter III homework due
October 21 Chapter III quiz taken
October 17 - 24 Chapter IV reading discussions
October 26 Chapter IV homework due
October 26 - 28 review Chapters III and IV
October 31 In class exam covering Chapters III and IV
November 2 - 14 Chapter V reading discussions
November 16 Chapter V homework due
November 21 Chapter V quiz taken
November 16
- December 7 Chapter VII reading discussions
December 9 Chapter VII homework due
December 9 - 12 review Chapters V and VII, and
course as whole
Wednesday December 14 8-11a Final exam, first half covering chapters V and
VII
second half covering course
Problem Sets:
Optional items are indicated by ( ). They may
be replaced by the replacement items. Submitting no question for
that item will result in zero points for that item.
Assignment for Chapter 1: To the student.1, 2.2, (2.6), 3.2, 3.9,
(4.2), 4.9, 4.11, 4.14, 5.2, 5.5, (5.7), 6.8, 6.11
For example, this means that you must complete the second exercise in
section 1. There is also a required exercise at the end of
the "to the student" section.
Replacements for Chapter 1:
1. Define a perfect number - be as precise as you can - probably use summation notation.
2. Find a counterexample to the following: If f is
continuous and differentiable on (a, b) and f(a) = f(b), then there
exists a real number c in (a, b) such that f'(c) = 0.
3. Prove and extend or disprove and salvage: The produce of any three consecutive integers is a multiple of 3.
4. Prove (using the givens in the appendix): A negative
integer multiplied by a negative integer yields a positive integer.
Assignment for Chapter 2: 7.4, 7.9, 7.14, 8.1, 8.7, 9.2, 9.6,
10.5, 11.16, (11.17)
Replacement for Chapter 2:
1. Use the results in 11.17 to prove (A n (A' u B))' u B = U (ask me if this notation is unclear - limitations of html).
Assignment for Chapter 3: 13.2, 13.9, 13.12, (14.4), 14.8, 14.12,
(15.11), 15.12, 16.10, (16.18), 16.19, 16.28
Replacements for Chapter 3:
1. Let R and S be the relations on Z defined as follows:
* a R b if and only if 2a + 3b = 0 mod 5
* a S b if and only if a + 3b = 0 mod 5
Are R and S equivalence relations? If not, which properties do they hold. Prove your results.
2. How many partitions are there of a set with n elements?
3. Present a combinatorial proof of: 
Assignment for Chapter 4: (19.5) 19.7, 19.9, 21.5, 21.8 (valued as
6 questions)
Replacement for Chapter 4:
1. If n is a positive integer, then the smallest perfect square that exceeds n^2 is n^2 + 2n + 1
Assignment for Chapter 5: (23.6), 23.9, 23.11, 23.12,
(23.14), 23.15, 24.4, 24.9, 25.4, 25.12, 26.2, 26.12
Replacements for Chapter 5:
1. Prove Let A and B be two sets. If there exist
one-to-one functions f: A -> B and g: B -> A, then
there existsa function h: A -> B that is a bijection.
2. Describe a bijection from the closed interval [0, 1] onto the half-closed interval [0, 1).
Assignment for Chapter 7: 34.9, (35.10), 35.13, (36.3), 36.14
(valued as 5 questions), supplemental E-primes.
Replacements for Chapter 7:
1. Compute d = gcd(3913, 23177) by hand. Then find integers x, y so that 3913x + 23177y = d.
2. Prove: Let p be a prime and a be an integer relatively prime to p, then a^(p-1) = 1 mod p.
3. Prove: Let n be any integer, then 15 | 11n^8 + 4n^4.
Intended Learning Outcomes (General)
Upon successful completion of Math 239 a student will be able to
• Use both the propositional and predicate calculus of logic
• Perform set operations on finite and infinite collections of sets
• Determine attributes of functions and relations
• Determine countability and non-countability of infinite sets
• Produce rigorous proofs in various styles
(including induction) and in a variety of mathematical settings
• To use the definitions and known results of a
mathematical topic under study to understand and formulate propositions
about that topic, and to prove their validity through rigorous
argumentation.
Intended Learning Outcomes (Articulated--These are specific skills through which the general learning outcomes are achieved.)
Upon successful completion of Math 239, a student will be able to:
• Recognize logical propositions and translate them into symbolic form;
• Manipulate symbolic propositions according to the first order logical calculus;
• Recognize and produce valid symbolic arguments;
• Apply and interpret universal and existential quantifiers;
• Translate mathematical assertions into predicate notation;
• Recognize and use standard formats of proof—direct, contrapositive, contradiction;
• Perceive the relation of set operations and relations to logical operations;
• Use arbitrary collections of sets and indexing;
• Produce proofs of set identities symbolically and verbally;
• Construct proofs by induction and understand the context and appropriateness of this method of proof;
• Recognize well-defined functions;
• Establish properties of functions such as injectivity, surjectivity, and bijectivity;
• Find pre-images and direct images of sets;
• Recognize the concepts of countability and uncountability;
• Establish whether a given set is countable or not;
• Determine properties of a relation
on set such as reflexivity, symmetry and transitivity;
• Determine whether a relation is an equivalence relation;
• Produce the equivalence classes of a given equivalence relation
• Produce rigorous, articulate arguments and proofs in a variety of mathematical settings.