*Linear Algebra* is a Free text for an undergraduate mathematics course. It covers the standard topics: Gauss's method, vector spaces, linear maps, determinants, and eigenvalues and eigenvectors.

The PDF of the *Linear Algebra*, and of the answer book, the beamer slides, and the lab manual, are at the book's home page joshua.smcvt.edu/linearalgebra. You can also buy hard copies for less than the cost of copying and binding. These are available from Amazon for single-person copies or from the college bookstore source if you are an instructor; see the web page for more information and links.

# Summary

What sets this book apart is its developmental approach. *Linear Algebra* does not assume that students are mathematically sophisticated so it includes lots of examples, lots of motivation, and clear exposition. But it does assume that the goal is to make the students more sophisticated so everything is proved, it nudges readers to see the advantages of a more advanced viewpoint, and in particular vector spaces and linear maps appear as early as is practical.

In addition to the main text, every chapter ends with a few Topics that illustrate applications or extensions of the material. These are suitable for independent reading, for group work, or for a one-day presentation as a break.

There are many exercise in each section. The answer book contains a completely-worked solution for every exercise, including the proofs. The book and answer PDFs are set up so that if you click on the question then you are taken to the answer and if you click on the answer you come back to the question.

Besides the answer book, there are beamer slides for classroom use. These are keyed to the text, including that they use the same wording and numbering for theorems, definitions, etc. (The version of the slides that I use passes over some proofs to instead do illustrative examples; there is also a version with all the proofs.)

And, there is a lab manual for computer work, using *Sage*. It introduces students to doing linear algebra on a computer and also introduces some important applications that are difficult by hand but easy on a machine.

# License

*Linear Algebra* is Free. You can use it under the GNU Free Documentation license or under a Creative Common Share Alike license, at your choice.

This text has been available online for over twenty years. It has been used in hundreds of classrooms. It has also been widely used for self-study, both as a supplement to another text that a student has been assigned in a class and as a main text for independent learning.

# Author

I am a math professor at Saint Michael's College in Colchester Vermont.

I am glad to hear from users, for example from instructors with reports and suggestions from their experience, but particularly with bug reports. You will have the most luck with my contact information on the book's home page joshua.smcvt.edu/linearalgebra.