# Teaching at UC Davis, Winter 2020

TEACHER OFFICE HOURS: M 03:05-04:05PM  and  R 01:30-03:00PM

MAT-145 s001, Combinatorics: MWF 1210-0100 PM                                              MAT-145 s002, Combinatorics: MWF 0210-0300 PM

TA: Brett Leroux (leroux AT math.ucdavis.edu)    Office Hours: T 12-1PM,   T 3-4PM   and  W 10AM-12.  Room: 2142 Academic Surge.

TEXTBOOK: Combinatorics and Graph Theory, 2nd Edition by Harris, Hirst and Mossinghoff. Springer. 2008.

• Sample Midterm1.            Solutions.
• Hints to some Problems:     2.2.8.     2.5.13
• Midterm 1 will be based on the Suggested Exercises and Homeworks 1 and 2. It means Sections:   2.1, 2.2, 2.3, 2.4, 2.5 and 2.6.4
• Remember to bring your photo ID, pen/pencil and eraser ONLY.
• Sample Midterm 2.           Solutions.
• Midterm 2 will be based on the Sugg. Exercises and HW 3 and 4. Sections:  2.6.5, 2.6.2, 1.1.2, 1.1.3, 1.3.1, 1.3.2, 1.4.2 and 1.5.1.
• TakeHome Exam will cover ALL sections!
• IMPORTANT FINAL MODIFICATIONS (Due to current global health issues):
1. There will be NO Final Exam.
2. All students have been assigned a grade in Canvas, proportional to current sum/250 points. If you want this to be your final grade, then you are set, have a nice break!
3. If you want to improve your grade, you will have the option to submit a TakeHome Exam, worth 100 points (so final grade will be proportional to sum/350 points), to be released in this site on 03/17 at 6pm, and due on 03/18 at 3pm, online submission via canvas.
4. Let me know about your choice (via email) by 03/18 at 3pm.
5. If you have any questions, let us communicate via email.

SUGGESTED EXERCISES (By section)

• 2.1:  1, 2, 3, 4, 8, 9, 11, 12, 14.
• 2.2:  2, 3, 5, 6, 7, 8, 10, 11.
• Extra: Use induction to prove:   $$(a) \ 11^n-6$$ is divisible by 5, $$\forall n\in\mathbb N$$.        $$(b) \ n^2<2^n,\ \forall n\ge 5$$.
• 2.3:  1, 2, 3, 4, 5, 6, 8, 9, 10.
• 2.4:  1, 2, 3, 5, 6, 7, 8, 9, 10, 13.
• 2.5:  1, 2, 3, 4, 6, 7, 8, 9, 12.
• 2.6.4:  All of them.
• 2.6.5:  All except Problem 5.
• 2.6.2:  1, 3, 4, 5, 6, 9.
• 1.1.1:  1, 3.
• 1.1.2:  1, 3, 4, 5, 6, 8, 12, 14, 16.
• 1.1.3:  1, 2, 3, 6, 7.
• 1.3.1:  1, 2, 3, 4.
• 1.3.2:  1, 2, 3, 4, 7, 8, 10, 12.
• 1.4.1:  1, 2, 3, 4.
• 1.4.2:  1, 2, 4, 5, 6, 8.
• 1.5.1:  1, 2, 3, 4, 5, 6.
• 1.5.2:  All of them.
• 1.7.1:  1, 2, 3.
• 1.7.2:  1, 2, 3, 4, 5, 6.
• 1.8.1:  1, 3, 4, 5.
• 1.8.2:   1, 2, 4, 5.
• 2.10.2:  2, 3, 4, 5, 6, 7, 8.

HOMEWORKS: All problems are worth the same, but elegant solutions to Difficulty 3 Problems could provide bonus points for Midterms.

1. Homework_1.  Due on 01/22.
2. Homework_2.  Due on 01/29.
3. Homework_3.  Due on 02/14.
4. Homework_4.  Due on 02/24.
5. Homework_5.  Due on 03/13.

OPTIONAL READING: (For examples and exercises)

• Discrete Mathematics: Elementary and Beyond by Lovász, Pelikán, and Vesztergombi. Springer. 2003.

• 5 Homeworks: 10 points each         (due dates: Hw1: 1/22  //  Hw2: 1/29  //  Hw3, Hw4, Hw5: TBA)
• Midterm Exam 1 (Friday, JAN 31, in class): 100 points,
• Midterm Exam 2 (Friday, FEB 28, in class): 100 points,
• Final (s001: Wednesday, March 18 // 1:00-3:00 p.m.//Room: TBA,----- s002: Tuesday, March 17 // 6:00-8:00 p.m.//Room: TBA): 200 points,
• TOTAL: 450 points.

Grading curve: (There could be +s and -s)

• 0-40%: F
• 41-50%: D
• 51-65%: C
• 66-80%: B
• 81-100%: A