Up: Hensley's home page
This page will expand as the semester goes on. Look here frequently for further details.
Adobe pdf-readable First day handout. .
First week's homework: The first homework assignment is section 1.1
problems 3bd, 6ag, and 1.2 problems 2e, 3d, 5aj, 7,9, 15, 22a. (Here, bd means
b and d but not c, and so forth.)
Notes on the first lecture PDF file..
Notes on the second lecture PDF Friday Sept 1 lecture overview .
Notes on Sept 4 lecture. Also the next homework is included. Sept 4 PDF file.
Notes on Sept 6 class. Problems are stated and then solutions. Sept 6 PDF problems and solutions file.
Notes on Sept 8 class. Sept 8 PDF file. I left out mention of upper and lower triangular. You do have a textbook and I can't improve on it with respect to upper and lower triangular, except to note that there are matrices that cannot be put into LU form. The matrix with 1s in position 1,2 and 2,1 and 0s in positions 1,1 and 2,2 is an example. But these are exceptional cases.
Homework for Sept 18 is p 94 numbers 1, 3g [do it by cofactors], 3h [do it by row operations], 6, and 9. But with 9, you may use either the cofactors definition from the text of the permutations-based definition from lecture.
On page 101, numbers 2, 4, 10, 11, 12. And on page 109, numbers 2d and 3.
Notes for Sept 11. Determinants and some properties. Homework is now listed separately; that should make it easier to find.
Notes for Sept 13. Permutations, cofactors, and all that jazz.
Notes for Sept 15. [Updated to correct amputation of solution pages] Assorted problems and solutions.
Homework for Sept 25 (not 18th!) is section 3.1 numbers 1, 8, 9, 12, section 3.2 [not 2.2] numbers 2, 3, 8, 11, 19, 20 (modified).
Pages are 122 and 131-132 respectively.
Notes for Sept 18. New topic, some key definitions. vector spaces defined.
Notes for Sept 20. More definitions. null space, row space, span, etc. defined.
Notes for Sept 22. Exam 1 is on Sept 29. While we will be looking at new material next week, at least in part, the topics for the exam end with chapter 3 section 3. We've covered all of that apart from the \emph{Wronskian}, which also will not be on (this) test.
Some of the exam problems will be mainly a matter of terminology. Some will be mainly a matter of computing. You can expect to be given a matrix, for example, and find its inverse or row-reduce it. You can expect to be given a row-reduced augmented matrix and find the corresponding solution set.
You can be expected to be asked to compute a determinant. And, some of the questions will be in the spirit of the ones we've been working through on Fridays. Here's Friday Sept 22 problems and solutions.
Notes for Sept 25. Basis and dimension. read all about it. Also some discussion of how this fits in with the very beginnings of the course and solution sets of systems of linear equations.
Notes for Sept 27. Coefficient vector; sum and intersection of vector spaces. link here.
Reminder: Exam is Friday. Bring your own paper and writing instruments. No calculators.
Homework for [not Monday but Wednesday October 4] Section 3.3 p 143 1ce, 5,6,7,17,20. Section 3.4 p 149 5 and 11.
Homework for [not Monday but Wednesday Oct 11] Section 3.4 # 17, 18, Section 3.5 # 1a, 2a,5a(iii), 10. Section 3.6 # 1b, 3, 9, 10.
Synopsis of Friday Oct 6 problems session with solutions. .
Solutions to Exam 1. As noted, the actual exams had fewer questions each; material has been merged. PDF file.Long-winded, very thorough solutions are good for distribution but not expected as exam responses.
Synopsis of Oct 9 class definitions reviewed, with applications.
Homework for Monday Oct 16: Chapter 4, section 1 page 182 etc.: numbers 2, 4, 8, 10, 15, 17, 20.
Chapter 4 section 2 p 195 numbers 3b, 5, 9. Chapter 4 section 3 p 202 etc., numbers 1ae, 3, 7, 8, 13, 14, 15. Due following Monday Oct 23. (edit)
Synopsis of Oct 16 class linear transformations and matrices. .
Synopsis of Oct 18 class, first draft: similarity. First peek at orthogonality. .
Exhortation and invitation: This is going to be hard. It can't help but be hard. But there is a huge gap between hard and not doable. You-all can do this. Stay with it, accept that at times you'll be stuck and frustrated. Persist. Get help. Ask me questions, during or after class or in office hours. Understanding will come.