Math 103: Applied Algebra, Fall 2011

under construction!

Office hours:MW2:30-3:30 and by appt (just talk to me after class, or call or email)

Office: APM 5256, tel. (858) 534-2734

Teaching assistant: James Berglund

Computation of grade: The grade is computed from your scores in the final (40%), two midterms (20% each) and homework (20%).

Dates of exams:

Midterms: 10/26 and 11/16 (tentative)

Final: 12/6

Texts

  • Joseph Gallian, Contemporary abstract algebra, seventh edition.

    Tentative Syllabus We will primarily study groups, roughly covering chapters 0 until 10 or 11, and perhaps a chapter or two of part 3 (special topics). The following is a tentative syllabus, which probably will be modified a few times during the course.

    Week Monday Tuesday Wednesday Thursday Friday
    0
    Sep 19 
    Sep 21  Sep 23
    First day
    of classes
    Sep 28
    Chap 0 (Review)
    1
    Sep 26
    Chap 0 (Review)
    Sep 27
    Discussion
    Sep 28
    Chap 0, Chap 2
      Sep 30
    Chap 2
    2
    Oct 3
    Chap 1
    Oct 4
    Discussion
    Oct 5
    Chap 3
      Oct 7
    Chap 3
    3
    Oct 10
    Chap 4
    Oct 11
    Discussion
    Oct 12
    Chap 4
      Oct 14
    Chap 5
    4
    Oct 17
    Chap 5
    Oct 18
    Discussion
    Oct 19
    Chap 5apps
      Oct 21
    Chap 6
    5
    Oct 24
    Chap 5/6
    Oct 25
    Discussion
    Oct 26
    Exam 1
      Oct 28
    Chap 6
    6
    Oct 31
    Chap 6/7
    Nov 1
    Discussion
    Nov 2
    Chap 7
      Nov 4
    Chap 9
    7
    Nov 7
    Chap 9
    Nov 8
    Discussion
    Nov 9
    Chap 8
      Nov 11
    Veteran's
    Day
    8
    Nov 14
    Chap 10
    Nov 15
    Discussion
    Nov 16
    Exam 2
      Nov 18
    Chap 10
    9
    Nov 21
    Chap 10
    Nov 22
    Discussion
    Nov 23
    Chap 10
    Thanksgiving
    Thanksgiving
    10 Nov 28
    Chap 8
    Nov 29
    Discussion
    Nov 30
    Applications
      Dec 2
    Catch-up
    11   Dec 6
    Final Exam
    11:30am-2:30pm
         

    Homework assignments

    Homeworks need to be turned in on or before the stated date, usually a Friday, by 2pm. There is a drop box on the 6th floor of APM. No homework needs to be turned in in weeks when a midterm is scheduled. However, some of the listed problems may also be part of the material being asked for the midterm. It is very important that you do the homework problems as most of the exam problems will be variations of homework problems.

    Disclaimer: I will try to get the homework assignment on the net in time. Due to time and other limitations, this may not always be possible. The fact that there is no assignment posted for a particular date does therefore NOT necessarily mean that no homework is due.

    for Sept 30: : Chapter 0: #8, 10, 12, Use Euclidean algorithm to calculate gcd(34, 126) and express it as a linear combination of 34 and 126; 20, 21, 28, 36, 38, 54,

    for Oct 7:: Chapter 1: #4, 6, 10. Chapter 2: #6, 11, 12, 16, 20, 22, 24, 28, 35 Note: You may assume without proof in #11 that multiplication of matrices is associative.

    Additional Problem: We have seen that the rational numbers Q with multiplication can only be made into a group if we remove 0. Question: Could we make Q into a group with the usual multiplication if we add to it an inverse of 0 called \infty? What would be the multiplication with \infty? Either show that all group axioms would be satisfied, or find a contradiction.

    for October 14: Chapter 3: #2, 8, 10, 12, 18, 25, 28, 42, 52, 59a,b, Chapter 4: #1, 4, 8, 12, 14, 16, 18

    for October 21: Chapter 4: #22, 40, 45, 54 (hint: consider the order of an element in the intersection), 56 (hint: prove first that it is enough to show that U(2^n) contains two distinct elements of order 2, using theorems in the book) Chapter 5: #3d, 4, 18, 28, 36, 6 (we will define A_n on Wednesday, or look it up on page 105/106), 8, 12, 24,

    for November 4: Chapter 6: #4, 10, 18, 20, 22, 24, 25 Extra problems for practice (do not hand in): Chapter 6: #1, 3, 5, 7, 19 (or wait with looking at the problems until preparing for next midterm). It is recommended that you start looking at the problems of the next assignment, which will be longer, and you have to turn the problems in sooner due to a holiday).

    for November 11 (Friday is a holiday): Chapter 7: #2, 6, 8, 10, 16, 20, 22, 24, 26, Chapter 9: #8, 10, 12, 16, 18

    for November 23 (Wednesday, because of Thanksgiving): Chapter 9: #37, 38, 70, Chapter 10: #2, 10, 14, 20, 24,

    for December 2: Chapter 10: #32, 54, Chapter 8: #2, 4, 6, 12, 26, 28, 50, 56, 64

    Remark about homomorphisms

    ----------------------------------------------------------------------------------------------------------------------------------------------

    Final: Essentially the same rules apply for the final as they do for the midterms: You are allowed one hand-written cheat sheet (both sides), but no other notes, books or calculators. The material will go over what we covered in class and homework from Chapter 0 until including Chapter 10. The problems will be similar to assigned problems or problems from practice exams. Below is a practice exam

    Practice final

    Office hours in finals week: M2-3, I'll be around in my office at 5 as well, but may not stay very long if nobody shows up. --------------------------------------------------------------------------------------------------------------------------------------------

    Midterm I: The first midterm will take place Wednesday, October 26, in class. You are allowed one hand-written cheat sheet (both sides), but no calculators or books. The material will go until this homework assignment; however, you will only need to know very basic things from Chapter 5, such as how to do calculations with permutations. Below you find a practice midterm from a previous class. Cover the solutions first. If you can not do the problem, you should have spent thinking about it for at least ten to 15 minutes before looking at the solutions.

    Practice test for Midterm I

    The exam problems will be similar to homework problems or practice test problems. So possible problems could deal with subgroups of general groups, of cyclic groups, orders of elements in cyclic groups or U(n). It is unlikely that you will have to do problems from Chapter 0 by themselves. But it could happen that you would have to calculate the gcd or lcm of numbers in connection with other problems, or that you may have to express the gcd as a linear combination of the original numbers.

    You may ask questions on Monday in class, or in my and the TA's office hours, or in the TA section. Don't be shy about it.

    Midterm II The material will go until the last homework assignment, but without the material of Chapter 9. So you only need to know material until Chapter 7. The same rules will apply as for Midterm I. The problems will be similar to homework problems or problems in the practice exam below. Please start with preparing now for your exam, so that you can ask questions in class, section and/or office hours next week.

    Practice test for Midterm II