2006 april 27 / e-mail me

- Apr 27: The third exam has been graded. You can pick it up in office hours. Data have been posted below.
- Apr 26: Office hours in the coming week are Fri 1:30-2:20+, Sat 2:00-3:00+, Sun 2:00-3:00+, Tue 3:00-4:00+, Wed 3:00-4:00+. The "+" denotes that I will stay later if there are students talking to me. The final exam is Thursday, May 4, 7-10 PM, in our usual room. I will not be available on Thursday before the final.
- Apr 24: I have added the third exam below.
- Apr 14: I have added statistics for the second exam below.
- Apr 10: I have added the second exam below.
- Apr 5: Here is a PDF of the isomorphisms handout from class today.
- Mar 17: Your second exam will be an unlimited-time, open-book take-home exam. It will begin Fri Mar 24 and will be due on Wed Mar 29. There is no real need to study for such a test, but before the 24th you might want to
- make a copy of the homework that you're handing in on the 24th
- copy class notes from a classmate, for any lecture that you missed
- get as much of your other work out of the way as possible
- talk to me about any old concepts that you never quite understood

- Mar 5: This Friday the homework due is Section 3.4 and Section 3.5#2, which has just been added to the syllabus.
- Feb 22: Here is my brief summary of the 3D graphics stuff we've done, with the problems that you need to hand in on Friday.
- Feb 20: Exam 1 data has been posted below.
- Feb 16: I have posted the first exam below, with and without answers. I am not yet done grading it, however.
- Feb 9: Your first exam will take place in class on next Wednesday, February 15. It covers all material up to the lecture on Febrary 8 on section 2.2. There will be a mix of computations, short conceptual questions, and longer proofs. I will announce extra office hours on Monday and Tuesday to help you prepare.
- Feb 2: Here are my sample solutions and remarks on homework 2.
- Jan 18: Here are my sample solutions and remarks on homework 1. You should submit revised solutions on Monday. During the revision process, you must have one other student in the class read your solutions and comment on them.
- Jan 14: The first homework assignment (section 1.1) is due this Wednesday.
- Jan 11: Office hours have been set; see below. Also, I've indicated roughly when the exams will occur.

The textbook is *Linear Algebra: A Geometric Approach*, by Shifrin and Adams. Linear algebra is a foundational subject with theoretical and practical applications in every area of mathematics and the natural and social sciences. The course work itself is a mixture of computations, proofs/concepts, and applications. Here's how you get in contact with me:

- Dr. Joshua Davis
- E-mail: see here
- Office: 033 Physics/Math
- Office phone: 660-2823
- Office hours: Tue 3:05-3:55, Wed 3:05-3:55, Fri 1:30-2:20, and by appointment; to make an appointment, pick a free time from my weekly schedule and e-mail me

The detailed schedule, with problems, is here. Your final grade is determined as follows.

- Homework: 15%
- Exam 1 (Feb 15): 20%
- Exam 2 (Mar 29?): 20%
- Exam 3 (Apr 26?): 20%
- Final Exam (May 4): 25%

You have work due every time we meet:

- Attend class, with your textbook, ready to participate in discussions and group work.
- Read the textbook before or after class to get another perspective on the material.
- Do not wait for assignments to come due, to begin work on them; after each class period, tackle all of the problems that you can. I am happy to discuss such problems before and after class.

If you cannot make it to class, then you should check with a classmate or with me to see what was missed. If your absence is due to a serious, incapacitating illness, and you are willing to vouch for this under the Duke Community Standard, then you may do so at Short-Term Illness Notification; for then the absence is excused, and I won't penalize you for missing a class activity, such as handing in homework or taking a test.

Your homework should be neat and complete, with the problems done in the order they were assigned, and clearly marked. Staple your assignment into a single packet to be graded. If your paper is messy from revisions, erasures, etc., then you may need to recopy it. Show your work, and give simplified, exact answers. If a classmate were to read one of your solutions, she or he should be able to understand what the problem was and how you solved it. In other words, **your solution should be well-written and self-explanatory**. At the top of the first page of your assignment, write your name and write and sign the short pledge: "I have adhered to the Duke Community Standard."

Keep in mind that, while **you are encouraged to work with others** on homework and when preparing for tests, **the written work that you submit must be your own**. In particular, you may not copy someone else's work or allow them to copy yours.

Depending on time constraints, perhaps only a subset of your homework problems may be graded. In order to ensure full credit, do all of the assigned problems. Also, if the grader cannot easily understand your paper, for example because it is messy or the problems are out of order, then you may lose credit.

A major component of this course is learning how to write rigorous mathematical arguments in the mathematical idiom. **We will do a lot of work on writing**. I will give you examples and feedback to help you write. Your homework will be graded for exposition as well as content. On some assignments you may be required to do multiple drafts.

I want all of my students to work hard, learn a lot of math, and earn a good grade. For most students, this course will be dramatically different from their earlier math courses. Philosophically speaking, the concepts are not difficult; after all, it's just algebra, and "linear" is essentially a synonym for "easy". On the other hand, you are expected to understand these concepts deeply (and geometrically, and abstractly), and to employ them in both calculations and proofs. Furthermore, you are expected to write your solutions rigorously, in the mathematical idiom. Here are my recommendations:

- Do all of the homework problems. If some concept is still unclear to you, do more problems on it. Once you truly understand it, you will be able to make up your own problems and solve them. Unfortunately, doing problems is the best way to learn math.
- Work with other students as much as possible. This is more fun than solitary work, and explaining math to others really helps you understand it better yourself.
- Talk to me in office hours, or ask homework questions before and after class. Every student is expected to visit me at least once in office hours this semester. Your writing may especially benefit from one-on-one discussion.

Here are the exams we've taken, both with and without answers, and some data about how the students performed. This should give you an idea of how you're doing relative to the class. I will wait until all of the work is done, at the end of the semester, to assign formal letter grades.

Exam 1 | Exam 2 | Exam 3 | |
---|---|---|---|

Points Possible | 100 | 160 | 80 |

Median | 54 | 132 | 62 |

Mean | 54 | 126 | 60 |

Standard deviation | 10 | 25 | 13 |

Fraction of students within 1 standard deviation of the mean | 10/16 | 14/16 | 9/16 |

Exam (blank) | exam1.pdf | exam2.pdf | exam3.pdf |

Exam (answers) | exam1a.pdf | exam2a.pdf | exam3a.pdf |