General information for Math 250:1 & 5, spring 2011


Math 250
Here is the catalog description of the course:

01:640:250 Introductory Linear Algebra (3)
Prerequisite: CALC2 or 01:640:136 or 138.
Systems of linear equations, Gaussian elimination, matrices and determinants, vectors in two- and three-dimensional Euclidean space, vector spaces, introduction to eigenvalues and eigenvectors. Possible additional topics: systems of linear inequalities and systems of differential equations.

The ideas and computations of linear algebra are everywhere in mathematics and its applications. They are used in every area of science, technology, and engineering.

I last taught linear algebra many years ago. At that time matrices were triangular (to the right are some student notes from that course written on a rock). Since then, matrices have evolved and become four-sided: they are rectangular.

More spectacularly, the ideas of linear algebra led directly to the overwhelming success of Google (a discussion of the specific ideas involved is here with some supporting computational framework here).

I believe it is nearly educational malpractice to present linear algebra without some computational support in this century, but we will try to teach and learn without such. In "real life", the ideas and algorithms of linear algebra are almost always implemented by silicon friends but in this course we will be stuck with examples that can be done by hand.

Not only are real examples usually on a much larger scale than what can be presented in Math 250, but also much of linear algebra uses only (?) arithmetic (+,–,x,/) so all sorts of collections of "numbers" or any objects which can be added, subtracted, multiplied, and divided are candidates for linear algebra and its ideas and computations. This includes such familiar collections as the rational numbers (fractions involving integers) and the complex numbers (a+bi with a and b real and i2=–1) and also includes less familiar examples such as finite fields, which students who study digital signal processing and the finite Fourier transform will learn much about. That sort of linear algebra is also important in coding theory and cryptography.

The phrase "linear algebra" has almost two and a half million Google links today. There is certainly enough information available! If you would like to see some simple but very clever elementary applications of linear algebra, look at Thirty-three Miniatures: Mathematical and Algorithmic Applications of Linear Algebra by Jiri Matousek (briefly: "This volume contains a collection of clever mathematical applications of linear algebra, mainly in combinatorics, geometry, and algorithms. Each chapter covers a single main result with motivation and full proof in at most ten pages and can be read independently of all other chapters (with minor exceptions), assuming only a modest background in linear algebra."), published by the American Mathematical Society. The Amazon web page about this book is here and allows you to see some of the contents.


Text
From the Math Department's web page:

Spence, Insel, & Friedberg: Elementary Linear Algebra: A Matrix Approach, 2nd Edition , Prentice-Hall   (ISBN # 978-0-13-187141-0).

The authors of the textbook also have a companion web site containing supplementary material, including multiple choice tests covering the topics in the course. Students can take these tests on-line and have graded results of each test e-mailed to themselves (and their instructors, if desired).

Additionally, lists of errors in the text and the student solutions manual can be found here.

I hope to follow the suggested syllabus for the course and would like students to do the suggested homework problems. I'll ask that solutions to some textbook problems be handed in.
Here are both the syllabus and the suggested homework list combined so you can save paper by printing this file two-sided.

One student (Ms. Steiner) reported that the website http://www.onlinemathlearning.com/linear-algebra-help.html has links to some helpful video tutorials about linear algebra.

Every computational algebra system I know (certainly including Maple, Mathematica, and Matlab) supports linear algebra very well. You may wish to investigate this. Almost surely you'll need to learn how to use such programs sometime in your life -- in school or at work. Here is a webpage at Duke University which has modules which can help you learn about linear algebra computations in Maple, Mathematica, Matlab, and Mathcad.


Background
You need to know how to do arithmetic and how to think logically.
One interesting aspect of the course is the contrast between formulas and algorithms. This course can briefly (and almost accurately!) be described as one algorithm and how to interpret the output. What may surprise students is that although explicit formulas can sometimes be given to get the computational results desired, the formulas are usually quite inefficient. I'll try to address this contrast during the course. The logical thought mentioned above is needed to deal with the output of the algorithms. We will solve systems of linear equations. Because we're doing this by hand, most of our systems will have a relatively small number of variables and equations. You need to learn to cope with many variables and equations. Therefore you need to learn the underlying logic: definitions and theorems. The simple examples we will do in this course are generally not realistic, and the logic will prepare you for what you will need to do.


Instructor
The lecturer is S. Greenfield.
Office: Hill 542 on Busch Campus; (732) 445-2390 X3074 (there's an answering machine);
My e-mail address is greenfie@math.rutgers.edu. I usually check e-mail several times a day, so that's probably the best way to leave a message.
Office hours: Monday and Wednesday from 3 to 4 PM and by appointment (e-mail is best for arranging appointments).


Grading


Maintained by greenfie@math.rutgers.edu and last modified 1/15/2011.