# Math 221

# Linear Algebra

**Time, location:** TTh 11:30-12:45 (section 003), MSC W302

**Instructor:** Patrick Corn, MSC W402, pcorn (at) mathcs (dot) emory
(dot) edu

**Office hours:** MW 2-3, or anytime in the afternoon except Friday
and when I'm teaching. Extra office hours will always be available upon
request.

**Course web page:** You're looking at it.

**Final exam:** W302, Wednesday May 5, 8:30 - 11:00 am.

**Book:** Linear Algebra and Its Applications, 3rd edition (update), Lay.

**Syllabus:** Chapter 1 (except 1.6), Chapter 2 (except 2.5, 2.6, and 2.7),
Chapter 3 (sections 1-3), Chapter 5 (sections 1-3), Chapter 6, and 7.1; plus
whatever we can get to after that.

**Homework and tests:** Homework will be assigned after every class, due in class a week after it is assigned. Since the class has a grader, all homeworks will be for credit (except for
Homework 1). There will not be any weekly quizzes. For grading purposes, we will drop your two lowest homework scores. No late homeworks will be accepted. All the homeworks will be posted
solely to this webpage. Check it routinely.

There will be three tests, given in class. They are tentatively scheduled for **February 11, March 18**, and **April 15**. We'll finalize
those dates far in advance; I do not expect to change them. If you have a potential conflict, you must let me know as soon as possible or you
may suffer dire consequences!

The final exam will be comprehensive. The grading breakdown is as follows:

**Homework** 40%

**Tests** 15% each

**Final** 25%

If you do the math, you will notice that this adds up to 110%. This is a built-in "fudge factor" to minimize the effect of bad days--the final
grade will count the worst of your five performances for 10% less than it would otherwise.

**Comments about the content of the course:** Linear algebra is one of the most fundamental areas of mathematics. It has a myriad of
applications in mathematics and the sciences. It is beautiful, clean, and powerful. It is also difficult, at least at first. This class will bear
little resemblance to the calculus classes you have taken, both in content and in form. Certainly you will be asked to do computations of various
types, but what may be less familiar is the emphasis on abstract thought and logical reasoning. You will be asked to understand proofs, and to
create your own. All of this takes practice and time.

Read the "Note to Students" at the beginning of the book, and "How to Study Linear Algebra" at the beginning of the Study Guide. The advice it
gives is excellent.

**Miscellaneous comments:** In no particular order:

Collaboration is not only permitted, it is encouraged. If you work in a group on an assignment for credit, make
sure that your solutions are written in your own words. Outright copying is a violation of the honor code (and is generally fairly easy to spot).

Show your work on assignments and tests, even when you are not explicitly asked to do so.

Calculators are ok for checking your work and carrying out tedious computations, but they won't be available on
tests.

The book's website is http://www.laylinalgebra.com, and is worth
bookmarking.

Attendance is not, strictly speaking, mandatory. In practice, it is essential for success in the class.

**Homework 1, to be completed by 1/21:** Read **section 1.1** and do practice problems 1-4 and exercises
1, 9, 11, 13, 15, 17, 23, 25.

**Homework 2, due 1/26:** Read **section 1.2** and do exercises 2, 4, 6, 12, 14, 16, 21, 22.

**Homework 3, due 1/28:** Read **section 1.3** and do exercises 4, 6, 10, 12, 18, 23, 24, 26.

**Homework 4, due 2/2:** Read **section 1.4** and do exercises 8, 12, 14, 16, 18, 22, 23, 24, 31, 32.

**Homework 5, due 2/4:** Read **section 1.5** and do exercises 6, 8, 12, 16, 23, 24, 30, 32, 38.

**Homework 6, due 2/9:** Read **section 1.7** and do exercises 6, 10, 18, 21, 22, 28, 30, 36, 38, 39.

**Homework 7, due 2/16:** Read **section 1.8** and do exercises 6, 10, 12, 16, 20, 21, 22, 24, 26, 31.

**Homework 8, due 2/18:** Read **section 1.9** and do exercises 2, 4, 8, 18, 23, 24, 26, 31, 32, 35.

**Homework 9, due 2/23:** Read **section 2.1** and do exercises 6, 10, 15, 16, 22, 23, 24, 26, 28.

**Homework 10, due 2/25:** Read **section
2.2** and do exercises 7, 9, 10, 16, 18, 22, 23, 24, 32, 34.

**Homework 11, due 3/2:** Read **section 2.3** and do exercises 6,
11, 12, 13, 18, 22, 28, 36. Also read **section 2.4** and do exercises
10, 21.

**Homework 12, due 3/4:** Read **section
2.8** and do exercises 6, 12, 14, 16, 18, 21, 22, 26, 32, 34.

**Homework 13, due 3/16:** Read **section
2.9** and do exercises 6, 10, 12, 14, 17, 18, 23, 24, 27, 28.

**Homework 14, due 3/25:** Read **section
3.1** and do exercises 4, 14, 18, 38, 39, 40. Also read **section 3.2** and do exercises 10, 22, 26, 27, 28.

**Homework 15, due 3/30:** Finish **section
3.2** and do exercises 14, 19, 32, 34, 40. Also read **section 3.3** and do exercises 6, 10, 12, 14, 16.

**Homework 16, due 4/1:** Read **section 5.1** and
do exercises 8, 12, 16, 20, 21, 22, 25, 26, 27, 29, 30.

**Homework 17, due 4/6:** Read **section
5.2** and do exercises 4, 6, 8, 10, 14, 18, 20, 21, 22, 25.

**Homework 18, due 4/8:** Read **section
5.3** and do exercises 6, 8, 10, 12, 14, 16, 18, 21, 22, 25.

**Homework 19, due 4/13:** Read **section 6.1** and do
exercises 12, 19, 20, 24, 28, 31. Also read **section 6.2** and do
exercises 10, 14, 20, 23, 24.

**Homework 20, due 4/20:** Read **section 6.3** and do
exercises 8, 12, 14, 20, 21, 22. Also read **section 6.4** and do
exercises 6, 12, 17ab, 18ab, 22.

**Homework 21, due 4/27:** Read **section 7.1** and do exercises
12, 16, 18, 22, 24, 25, 26, 27.