2006 april 27 / e-mail me

Math 104-01, Spring 2006



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:

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

In borderline cases, class participation and progress made through the semester are considered. Calculators are not permitted on any exams. You may use them while studying or doing your homework, but do not become dependent on them. Also, unless otherwise specified, we are always interested in exact answers (simplified as much as possible), and calculators rarely give the correct exact answers, so use them with care.

Daily obligations

You have work due every time we meet:

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.

How to succeed in this class

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:


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 1Exam 2Exam 3
Points Possible10016080
Standard deviation102513
Fraction of students within
1 standard deviation
of the mean
Exam (blank)exam1.pdfexam2.pdfexam3.pdf
Exam (answers)exam1a.pdfexam2a.pdfexam3a.pdf