MAT 241: Discrete Mathematics

Fall 2021

[ Current Week | Syllabus ]

Basic Information

Calendar

Daily/weekly schedule to be updated throughout the term; topics and exam dates are tentative and subject to change.

Before class, please read the textbook section(s) to be covered. Do the preview homework exercises. After class, start doing the review homework assigned that day as soon as possible. Unless otherwise stated, homework is due at 23:59 the night before the next class.

WeekMondayWednesdayFriday
Unit 1: sets, logic, proofs
11. 08/30 M

Introduction

hw02: Getting started

2. 09/01 W

1.1–1.3 introduction

hw03: A more typical homework

3. 09/03 F

2.1 sets

hw04: 2.1.2 # 1, 15bd, 16f, 18d.

2.1.4 # 1, 6ace, 11bc, 12d, 17a.

Fill out reflection1 on Moodle.

DMGN: Chapter 3, Logic.

2.2.4 # 1bdegkm.

2.3.4 # 2, 6a, 11, 13ac.

2.3.9 # 1, 2, 3, 4a, 7b.

Optional: sign up for a presentation.

2(Labor Day)4. 09/08 W

2.2–2.3 propositional logic

hw05: 2.2.4 # 1aln.

2.3.4 # 12.

2.3.9 # 4e, 8bc, 9bd, 10, 11, 13, 19, 21adf.

Read Why should I read a math book? on Moodle.

2.4.3 # 1, 2, 5a, 10ab.

Read Appendix G xor extended version.

5. 09/10 F

2.4 equivalence, inference

hw06: 2.4.3 # 8, 9, 10d, 11, 12b, 14.

Read Why are definitions important? on Moodle.

2.5.3 # 2, 3, 5, 9, 11, 14ab.

36. 09/13 M

2.5 boolean algebras

hw07: 2.5.3 # 4, 6 (idempotence only), 13, 15, 18abe, 23, 25.

Watch What good is boolean algebra? on Moodle.

2.6.2 # 1ac, 2b, 3bd, 9bc, 13af, 18b.

7. 09/15 W

2.6 predicate logic

hw08: 2.6.2 # 1df, 2d, 4b, 9d, 14c, 19de, 21.

Read Why should I memorize? on Moodle.

DMGN: Chapter 4, Elementary Number Theory.

3.1.3 # 1, 4ac.

3.2.6 1ad, 8c.

8. 09/17 F

3.1 proofs

3.2 elementary number theory

hw09: 3.1.3 # 4b.

3.2.6 # 1b, 8a, 10, 11, 13, 14.

DMGN: Chapter 5, Proof.

Re-read Appendix G xor extended version.

3.3.10 # 1a, 4, 10, 15, 20, 22.

Read first 5 sections of "topics and tips" for exam1, linked below.

49. 09/20 M

3.3 proof strategies

hw10: 3.3.10 # 9, 12, 16, 19, 27, 30, 37, 39*, 42, 44.

* 39: extra credit part will not be graded.

DMGN: Chapter 6, Mathematical Induction.

3.5.6 # 1a*.

* 1a: use the same formatting style as in textbook examples (proof of Theorem 3.54, Example 3.35, etc.). Clearly label the step where you use the inductive hypothesis.

Read logistics section of "topics and tips" for exam1.

10. 09/22 W

3.5 induction

hw11: 3.5.6 # 1c, 3, 5*, 9*, 11, 27a.

Continue to signpost your induction proofs as in the textbook, with clearly defined $P(n)$, clearly labelled base step, inductive step, and a conclusion sentence; also clearly label where you use the inductive hypothesis.

* 5: think and then read the solution; do not hand in.

* 9: show details (scratch work) of your discovery process.

Install and become familiar with Mathematica.

11. 09/24 F

(catch-up)

hw12: none; study for exam.

Unit 2: induction, algorithms
512. 09/27 M

exam1 (topics and tips)

hw13: 3.5.6 # 8, 15, 25, 27cd.

Read only some subsections.

3.4.7 # 1b, 7, 10, 15ad.

13. 09/29 W

3.4.{1,4} some applications

hw14: 3.4.7 # 1ad, 11*, 12*, 14*, 15bc.

* 11: must use the Euclidean Algorithm at least twice to find inverses (instead of trial and error).

* 12: you may use Mathematica or WolframAlpha. Show your work by writing down the command you used.

* 14: must use Theorem 3.46.

3.6.3 # 6, 9, 11, 12, 13, 15, 16, 21.

14. 10/01 F

3.6 creating proofs

hw15: 3.6.3 # 3, 4, 7, 14, 29, 34, 41.

DMGN: Chapter 7, (skip Counting 1 and jump to) Algorithms.

4.1.3 # 1*, 2, 4.

* 1: think first and then read the solution; do not hand in.

Note: use the pseudocode notation from the book. Do not hand in Java or C code (so no curly braces, || for or, % for mod, int, etc.).

615. 10/04 M

4.1 expressing algorithms

hw16: 4.1.3 # 10, 15.

Read 4.2.1, do exercises below (without using tools from 4.2.2), then read 4.2.2.

4.2.3 # 1*, 2*, 3, 4ac, 5ad.

* 1, 2: use Mma, with notebook on Moodle as a starting point.

16. 10/06 W

4.2.{0,1,2} big Oh and friends

hw17: 4.2.3 # 6, 12, 15, 16, 19cd.

4.2.5 # 1cd, 2, 3, 5, 7ab.

(fall break)
717. 10/11 M

4.2.4 algorithmic complexity

hw18: 4.2.3 # 20bd.

4.2.5 # 7cd, 8ac.

4.3.4 # 1*, 2*, 3, 4b, 7a, 9b.

* Download program from textbook website and run with Java. Use a computer in CC230 (the MathCS Lab) or your own computer if you have Java runtime system installed. Use built-in texts.

18. 10/13 W

4.3 pattern matching

hw19: 4.3.4 # 4c, 6c, 7c, 10b, 11b, 14cd, 15.

Use the format from the book; show tables where appropriate; and list entries in the BM Last table in alphabetical order.

Write neatly or type up your solution and export as PDF.

DMGN: Counting 1, Chapter 8 (but skip Counting 2).

5.1.6 # 1c, 2, 3, 5, 8, 10, 12.

19. 10/15 F

5.1 counting

hw20: 5.1.6 # 19, 21, 22, 26, 27, 28, 30, 31, 33, 40.

5.1.8 # 2, 4, 7, 10, 18c.

Unit 3: counting, recursion
820. 10/18 M

(catch-up)

hw21: none; study for exam.

21. 10/20 W

exam2 (topics and tips)

hw22: 5.1.6 # 44a.

5.1.8 # 15, 25, 29, 30.

Read the vcp overview; download the binaries, unzip, and run vcp.jar (do this in CC230 if you do not have Java installed); read the exposition and run the animations for the modules on Binomial Theorem, Counting Subsets, and Tulip. This is not optional.

5.2.3 # 1, 2, 4, 15.

22. 10/22 F

5.2 double counting

hw23: Read (and follow) the advice in items 11–13 of extended version of Appendix G.

5.2.3 # 3, 5, 7, 8, 16.

DMGN: Counting 2, Chapter 9.

5.3.3 # 1, 2, 3, 8, 11, 17, 26cd.

923. 10/25 M

5.3.1 pigeonhole principle

5.3.2 inclusion-exclusion

hw24: 5.2.3 # 10, 11*.

* 11: use a combinatorial proof.

5.3.3 # 9, 10, 12, 15, 16*, 18, 28.

* Here and always, provide enough details and justification.

DMGN: Chapter 10, Recursion.

7.1.7 # 1, 4, 7, 8.

(advising day)24. 10/29 F

7.1 recursion

(7.1.6 is optional as it requires some Calc 2.)

hw25: 5.2.3 # 17, 18 (combinatorial proof).

7.1.7 # 2, 9, 10, 11, 12a, 13, 14, 18*, 20*.

* 18, 20: Do not hand in.

7.2.5 # 1, 3bd, 4b.

1025. 11/01 M

7.2.{0,1} recurrence relations

hw26: 5.2.3 # 19 (combinatorial proof).

7.2.5 # 3a (simplify fully), 5a, 7.

Read.

7.2.5 # 11ab, 12ac, 16*.

* 16: produce (as always, with detailed justification) the recurrence relation, but do NOT solve the recurrence relation.

26. 11/03 W

7.2.{2,3,4} LHRRwCCs

hw27: 7.2.5 # 12d, 15, 16, 18bd, 19b, 21.

DMGN: Chapter 12, Graphs.

10.1.3 # 2acd, 3a, 5a, 6f, 7, 8, 9*.

* 9: there may be other even-degree vertices.

27. 11/05 F

10.1 graphs

hw28: 10.1.3 # 4c, 11*, 13, 15, 17, 19, 20.

* 11: explicitly transform this to a graph theory problem and then solve.

10.2.3 # 4 (no explanation necessary), 6a (explain your answer).

10.4.3 # 10 (we defined "isomorphism" in class, so you need NOT read 10.4).

Unit 4: graph theory
1128. 11/08 M

10.2 walks and connectivity

29. 11/10 W

exam3 (topics and tips)

hw30: 10.2.3 # 1, 7c, 11*, 13, 15, 16, 17.

* 11a: you may use a calculator or Mathematica.

10.3.3 # 1, 3, 5, 7.

30. 11/12 F

10.3 Euler and Hamilton

hw31: 10.3.3 # 8, 12, 13, 14, 15, 16.

10.5.4 # 3*, 9, 10ab, 18.

* 3: Recommendation: use Sandbox; first add all vertices in alphabetical order as the textbook so the labels are right; then add in all edges; then start dragging. When done, you may submit a screenshot (saved as PDF) or draw it by hand. To aid grading, your graph must have correct vertex labels.

As always, feel free to help each other understand the problem, but execute your solution yourself: it is unlikely that two students will arrive at exactly the same configuration. Do not plagiarize.

1231. 11/15 M

10.5 major graph theorems

- Proper drawings of planar graphs

- Colouring maps with four colours

hw32: 10.5.4 # 2, 10e, 11, 16, 17.

DMGN: Chapter 13, Trees.

11.1.1 # 6, 8, 12, 15 (do not assume the graph is a tree), 16 (read proof, do not hand in).

32. 11/17 W

11.1 trees

hw33: 11.1.1 # 1, 2, 4, 5, 18, 19.

No preview exercises; study for exam.

33. 11/19 F

(catch-up)

hw34: none; study for exam.

1334. 11/22 M

exam4 (topics and tips)

hw35: DMGN: Chapter 11, Finite-State Machines.

9.2.3 # 1abc, 2, 3, 4, 12ab.

(Thanksgiving)(Thanksgiving)
Unit 5: theory of computation
1435. 11/29 M

theory of computation

9.2 deterministic finite automata

hw36: 9.2.3 # 5ab, 6c, 9, 15, 17cd.

9.3.2 # 1abc, 5acd, 7ab.

36. 12/01 W

9.3 regular grammars

hw37: 9.3.2 # 6e, 8a, 11.

Worksheet # 2bcde.

Do not memorize Table 9.8.

9.4.3 # 1, 2, 3, 4.

37. 12/03 F

9.4 regular expressions

hw38: 9.4.3 # none.

Worksheet # 4abcde.

11.3.4 # 1, 2.

1538. 12/06 M

9.6.1 context-free grammars

11.3.1 parse trees

hw39: 11.3.4 # 4, 5, 6.

Do these review problems to prepare for class:

3.2.6 # 15 (induction on $k$), 20.

There are no preview problems. You may pre-read or not, up to you. We will prove Thm 3.50 in class.

39. 12/08 W

3.4.6 RSA cryptosystem

hw40: 3.4.7 # 9, 23*, 24*, 25*.

* Mathematica commands FactorInteger and Mod may be useful.

Fill out reflection2 on Moodle.

There are no preview problems. You may pre-read or not, up to you. We will prove Thm 4.20 in class.

40. 12/10 F

4.4 undecidability

Final Exam:
Section 1: 12/14 Tuesday 14:45–16:45
Section 2: 12/16 Thursday 14:45–16:45
(topics and tips)

Course Information

Overview

Goals. Discrete Mathematics is a course in Bethel's curriculum designed with three related driving goals:

  1. to help develop process skills to learn, do, and communicate mathematics.
  2. content: to introduce the wonderful mathematical world of discrete (as opposed to continuous) objects.
  3. to provide foundational knowledge, skills, and maturity required to succeed in subsequent math and computer science courses. In fact, this course is a (transitive) prerequisite for roughly half of the required Math or CS courses in our majors.
The first two goals are partially informed by the third, practical goal of preparing students for subsequent courses.

Topics. We will consider topics such as proofs, algorithms, counting, recursion, models of computation, graphs, and trees.

Objectives. We will use learning the content (secondary goal) as an opportunity to develop mathematical skills (primary goal). Specifically, I will guide you in learning how to:

Note that the primary objective of learning how to learn is much more important than the secondary content goal.

Structure and Adjustments

This is a remote, synchronous course: Due to the uncertain and ever-changing conditions the world is in, additional adjustments may need to be made. Thus: We will get through this semester together.

Grading

Your grade will be determined by a weighted arithmetic mean of various components with weights listed in the table on the right.
componentweight
Participation±3%
Homework and quizzes31%
Midterm exams48%
Cumulative final exam18%
The total score will be converted to a letter grade whose lower bounds are: 93% A, 90% A-, 87% B+, 83% B, 80% B-, 77% C+, 72% C, 69% C-, 66% D+, 60% D, 0% F.

Each letter grade has an associated number of required presentations (see below).

Note that there is no preset curve of how many of each letter grade will be given. If you all do A-level work, you will each get an A. As such, you are encouraged to help each other in the pursuit of perfection.

In many courses I intentionally make one exam harder than others, which gives me information (in a mathematical sense) in separating an A performance from an A- performance. Typically, I will let you know and adjust that exam's scores upward. What this means is that you should NOT care about how hard an exam is. If you do A-level work, you will get an A, regardless of the raw numerical score prior to adjustment.

Besides possibly adjusting scores upward for difficult exams, I also reserve the right to lower the grade cutoffs. Both of these help you. I will not hurt you by adjusting your exam scores downward or increasing the grade cutoffs.

Requirements

Whatever you do, work at it with all your heart, as working for the Lord, not for human masters, since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving.
- Colossians 3:23–24 NIV
I will be trying to make these verses true for me as I work with you throughout this course, and I hope that you will, too.

Attendance and participation. I expect you to attend class. You may not notice me taking attendance during class meetings, but I will notice if you are not in class. Occasional absences will not impact your grade because what I look for is not mere attendance, but engagement and participation.

Indeed, coming to class is not just about showing up; it is also about being fully engaged in the learning experience. If you have a question, others in the class may also be wondering the same thing. So, please speak up and ask questions anytime you need to. Not only will you be helping yourself, but also you will be helping your peers. Attending office hours is another great opportunity to ask questions.

Be mindful of others. Refrain from using mobile phones or laptops for activities unrelated to the learning process. There is research that suggests taking notes by hand is better for long-term retention (P. A. Mueller and D. M. Oppenheimer, The pen is mightier than the keyboard, Psychological Science 25 (2014), 1159–1168).

In general, you are expected to keep your video on most of the time to make your engagement more clear. Let me know if there are legitimate reasons why you need to be off-camera frequently.

It is my sincere hope that every one of you get all the points for attendance and participation.

Reading. The first objective is not to learn mathematics (content), but to learn how to learn mathematics (skill). Specifically, you will learn how to read a mathematical textbook.

Reading a math textbook is different from reading a novel. You must interrogate it. Ask questions. Work through exercises. Think about every sentence.
It will take time to get used to reading properly, but it will pay dividends if you do not give up. To hold you accountable to the reading, there will often be preview exercises due as part of daily homework based on the reading, before the topic is discussed in class.

Homework. Homework will be assigned most days. One of the three course objectives is to learn how to do mathematics. The goal of the homework is to give you an opportunity to continuously engage directly with the material. Some of the homework questions are meant to be challenging and to stretch you; simply put, I believe that the homework is where you will do the vast majority of your learning in this class. Grapple with the questions; talk to classmates about solution strategies if you are feeling stuck; do the homework.

Each homework must be scanned and uploaded to Moodle. Instructions for scanning will be given to you.

Homework is due at 23:59 the night before the next class after it was assigned, unless otherwise stated. In general, late work is not accepted. If there are special circumstances, talk to the instructor. To alleviate your anxiety from accidentally forgetting to submit homework before class, illness, emergencies, or other situations beyond your control, the lowest four (4) assignments will be dropped.

Because communicating results to others is an important skill, showing your work is as important as getting an answer. In many instances, credit will only be given if your work accompanies your answer. You are encouraged to collaborate, but what you turn in must be your own work. See "Learning integrity" and the collaboration policy below.

Presentations. Learning how to communicate mathematics is one of the three course objectives. You will communicate by writing (homework) and verbally (presentations). We will have opportunities for presentations on most class days. Presentations are required but will not be graded. Instead, students are asked to put in a genuine effort. The required minimum number of presentations is 4, 3, 2, 1, or 0 times to get an A, B, C, D, or F, respectively. I reserve the right to decrease the number of required presentations.

Exams. There are several in-class midterm exams (see calendar for a tentative schedule). Subsequent exams will mainly focus on the material covered since the previous exam, but will include previous material too. There will be a final exam during the official final exam period covering the entire course.

There are no make-up exams except in circumstances recognized by the instructor as beyond the control of the student. To receive this consideration, the instructor must be notified of the problem before the exam unless this is impossible, in which case as soon as possible.

Time outside of class. I expect a typical student to spend at least two to four hours outside of class for each hour in class. Some students need to spend a bit more than that (which is okay). If you are spending more than 15 hours per week on this course outside of class time, please come talk to me so we can find ways to help you learn the material without spending so much time.

Illness. You should make every effort to attend class when you are healthy. If you become ill, for your well-being, you should not come to class. Yes, this sounds like common sense, but it is tempting to try and power through as normal so as not to fall behind. If you become ill, or know that you will need to miss class for some reason, please contact me as soon as you are able, and we will work together to plan how you will keep up and/or make up any missed work.

Policies

Learning integrity.

Search me, O God, and know my heart;
Try me, and know my anxieties;
And see if there is any wicked way in me,
And lead me in the way everlasting.
- Psalm 139:23–24 NKJV
Collaborative work is an integral part of many successful ventures. As such, I expect that you should collaborate with your classmates a lot during your time in this course. However, it is important to understand that there is a big difference between thinking about and solving a problem as part of a group (which is good, both educationally and morally) and copying an answer or letting someone else copy your answer (which is bad, educationally and morally, and has punitive consequences).

In short, I trust you to maintain the utmost level of academic integrity in this course. Please do not break this trust; if you do, there will be repercussions. The formal policy below lays this out explicitly, and supplements Bethel's academic honesty policy.

Collaboration policy.

Accommodation policy. Bethel University is committed to accessibility for students with disabilities and the Office of Accessibility Resources and Services (OARS) is a resource to ensure students experience access. The instructor will provide accommodations after the student initiates the process.

OARS recommends the student and faculty discuss how accommodations may apply in the specific course. Accommodations cannot modify essential requirements or fundamentally alter the nature of the course. Consultation with OARS may be necessary to clarify reasonable accommodations based on the course. If there are any questions or concerns, connect with OARS at accessibility-services@bethel.edu or 651.638.6833.

Concerns and appeals. If you have any concerns regarding the course, your grades, or the instructor, see the instructor first. If needed, see Bethel's academic appeals policy.

Getting Help

If you need help there are multitude of resources you can use: