### Homework (Recommended Problems)

These exercises are not to be handed in for marking. Instead, you are encouraged to work on these selected exercises as part of your studying for the course.

- Here are the recommended homework problems for the
- 4th edition –
**Section 2.4 has been updated.** - 3rd edition

- 4th edition –

### Textbook Corrections

- Section 5.2: the answer to Question 7 has a typo: the first entry in the null space should be -1, not +1.
- Section 5.4: if you are wondering why the second column in the matrix Q has the bottom entry negative rather than the top, what they have is also an eigenvector for lambda=3, it's just been multiplied by -1. So if your answer is the same except the textbook's except that your top entry for the second column is the one that's negative, your answer is perfectly fine.

### Practice Questions

- Gilles' Practice Problems, including answers
- For Test #1, do questions 1 to 6, 8 (question 7 is from Section 2.4)
- For Test #2, do questions 7, 9 to 20
- For Test #3, do questions 21 to 28, 29(a)
- Susie has full solutions to these problems on her Math 251 website – look for the links in the table at the bottom of the page.

- Leah's Practice Problems, with Solutions Part I, Solutions Part II, and Solutions Part III
- For Test #1, do questions 1 to 6
- For Test #2, do questions 7, 8, 10 to 14
- For Test #3, do questions 16, 17, 18, 20, 23, 24, 26, 29