## Resources

#### Alternatives to the Book

While we will cover most of Holt in order, the underlying mathematics
is quite old and there are many other expositions. A few:

- My lecture notes (UW NetID required). These are not pretty or well-edited; they are written with only myself as the audience in mind. They may be modified at any time.
- S. Paul Smith has extensive and reasonably well-edited
notes
which are written at a somewhat more advanced level than Holt. See the "sermon" at the
end as well.
- Natalie Naehrig has some perhaps friendlier
notes, which are not quite as polished.
- Alex Young has turned the course into a series of "Paul's online math notes"-style
pages.
- Khan Academy has extensive material at this level, like
this.

#### Proofs

Linear algebra is at once extremely practical and quite abstract. Its theoretical underpinnings will be presented in lecture, frequently with proofs. Homework will often give you practice with hands-on examples, which later courses will build upon. Deciphering proofs is thus part of the course if you are to learn the material deeply. So, we will spend a small amount of lecture time early on discussing proof strategies.

You will be expected to produce some proofs on exams. To successfully construct proofs may require a change in your perspective. Being "mostly
right" is fine in much of life, but not when writing proofs.
Misunderstanding a definition or forgetting to check an assumption on a theorem can turn your
argument into complete nonsense. Here are
some examples
from students of the difference between "mostly right" definitions and fully rigorous ones.

#### Proofs

See the example proofs document.

#### Inverses

Here is a summary of the course's material on inverses.

#### Diagonalization

Here is a summary of the course's optional material on diagonalization.