### Chapter Two Catch Up Day 2

Date: 2017-02-15 15:45:00 +0000

Today we talked through some of the material from chapter 2 we find challenging.

### Permutation matrices

Date: 2017-02-13 23:50:00 +0000

Today we discussed permutation matrices, which help us encode the operations of row interchanges, much in the same way we have tried to use lower triangular matrices to track elimination steps.

### The LU decomposition

Date: 2017-02-10 12:00:00 +0000

We talked about how a careful watch on a forward pass of Gauss-Jordan elimination could be used to write a matrix in a special form:

### Catching Up

Date: 2017-02-08 20:10:00 +0000

My trip over the last weekend put me off schedule for this recap blog. But today I catch up! I have three days to write about.

### Elimination by Matrix

Date: 2017-02-01 00:00:00 +0000

We talked a little about using matrices to do elimination. The key here is that matrix multiplication can be organized by rows. Specifically, $$EA = U$$ can be computed by thinking of the rows of $$E$$ as holding coefficients for making linear combinations of the rows of $$A$$, and those linear combinations get stored in $$U$$. We did this quite explicitly when talking about task #32 when Mr Warner presented it. There his “permutation” matrix did the job of rearranging rows by using lots of ones and zeros to be coefficients.

### Solving Square Systems

Date: 2017-01-30 23:00:00 +0000

We discussed the mechanics of using “elimination and back-solving” for finding the solutions for square systems of equations. This is the start of a conversation about an algorithm that will allow us to efficiently handle the general basic linear algebra task.

### The Three Viewpoints

Date: 2017-01-28 12:15:00 +0000

I returned assessments and we discussed the process for reassessments. Then we discussed the three different geometric viewpoints on linear algebra:

### Assessment Day 1

Date: 2017-01-25 12:05:00 +0000

We took assessments today. These are just the first attempts!

### Chapter 1 Catch-up Day

Date: 2017-01-23 19:45:00 +0000

I collected more Knowledge Surveys. The class is up to 14/17. Those last three of you, bring them with you Wednesday!

### Matrices

Date: 2017-01-20 15:45:00 +0000

I started by collecting Knowledge Surveys. I only got 8 (out of 17) of those back. Since there were 5 absent students today, I guess that isn’t too bad. I hope to get the rest of them back on Monday. They should take less than 20 minutes to complete.

### The Knowledge Survey

Date: 2017-01-19 15:25:00 +0000

I distributed a Knowledge Survey yesterday. Though I have asked you to return it on Friday, perhaps you might find it valuable to have available during the semester. So, here is a link.

### The Dot Product

Date: 2017-01-18 15:00:00 +0000

Good work everyone. We are progressing nicely. Today was our first day to talk about the dot product. The cool thing is that the dot product contains lots of geometric information (lengths and angles!), and it also provides us a compact way of writing linear equations.

### Lab Day 1

Date: 2017-01-13 15:15:00 +0000

Today we practiced with SageMath through the SageMathCloud service. I will not collect the assignment I asked you to do in class today, but I still think you should do it. Also, I put the examples I did at the front of the room in your projects as a handout.

### Vector equations

Date: 2017-01-11 15:00:00 +0000

I am really pleased at the work you all did for today. Good job.

### Go!

Date: 2017-01-09 15:45:00 +0000

Good Job! Today we had our first run at solving typical linear-algebra style problems. We also had a few presentations, as Mr Warner, Mr Maynard, and Mr Bundt each took turns sharing their ideas.

### Welcome to Linear Algebra

Date: 2017-01-08 15:00:00 +0000

This course blog will serve a dual purpose. First, it will give us all a common record of what transpires in class. Second, it will be a way for me to make announcements.

Contact Prof Hitchman
Theron J Hitchman
Department of Mathematics 0506
University of Nothern Iowa
Cedar Falls, IA 50613-0506
Other Contact Information
Office: 327 Wright Hall
Phone: 319-273-2646
email: theron.hitchman@uni.edu
Course Information
Class Meetings:
MWF 2pm in WRT 105
Office Hours:
Use the link below to schedule a meeting during M-F 3-4:30pm.