# Chapter 3 Notes

@kellis1 @rbroussard3 @tspahn
I hope everyone’s semester is wrapping up nicely! I had a little extra time, so I started looking ahead to Chapter 3. I haven’t copied anything over yet, but wanted to get my thoughts in writing before we have our next meeting on Monday.

I was looking through Lippman’s chapter on linear programming, and I think a little restructuring of our chapters may be a good thing. I’m wondering if we should take Section 1.5 on linear inequalities and make it the first section of Chapter 3. So then Chapter 1 is all about solving and graphing linear equations. Chapter 2 is all about solving systems of equations, and Chapter 3 introduces inequalities, which leads to linear programming. Then we can take Lippman’s sections 3.3 and 3.5 and make each of them a section in Chapter 3. I’ve never used the Simplex Method that he talks about in section 3.4, which is why I’m inclined to leave it out, but if any of you use it, we can use that section as well.

So my proposed outline for Chapter 3 is:
-Section 1.5 from our current book
-Section 3.3 from Lippman’s book
-(if anyone uses the Simplex Method) Section 3.4 from Lippman’s book
-Section 3.5 from Lippman’s book

Thoughts?

Hi there. Still wrapping things up! But I have not used the Simplex Method either. I agree that we can leave it out. Let’s see what @rbroussard3 and @tspahn say about it. The outline you propose makes sense to me, so I am all for it.

This outline makes sense to me as well.

I have never used the simplex method either.

Do you think we need to include some inequalities in one variable - from Lippman’s chapter 3 section 1? I don’t think we need the parts about absolute value, but perhaps the simple one variable concept?

@kellis1 @rbroussard3 @tspahn
I edited Section 3.1. I took out everything about absolute value, but can add it back if we think it needs to be included. I don’t teach anything with absolute value in my class. I was having a lot of trouble with formatting. The LaTex worked fine, but when I would try to make something go to the next line, I had a lot of issues. Renae, let me know if you’re having trouble with that in 3.3.

I started looking at 3.4, but I realized those problems are more difficult than anything I teach. Lippman actually doesn’t work through the problems in this section because he covered the Simplex Method. These problems have constraints and objective functions dealing with 3 variables. What is covered in our Section 3.3 is the most extensive linear programming problems get in my class, but also remember algebra is not a prereq for my class. Do you all cover linear programming with 3 variables?

I haven’t made it out of 2.3 yet. I’ve had some struggles with all the formatting there. In particular, if cannot get this to code:

Any suggestions?

I’m going to try to import a picture of it as a place holder until I can figure it out.

$\begin{array}{rcl} A & \cdot & B \ 2 \times & \underbrace{3 \quad 3}_{\text {same }}& \times 3 \ & \end{array}$

@rbroussard3 Here’s the best I’ve come up with. I can’t figure out how to get the 3’s in the right place. I don’t think it’s a bad thing to leave it as a picture for now.

I got it to look like this: top option is a picture bottom option coded with underbrace

Anyone have a preference?

underbracket is apparently a command - but not in pressbooks

I didn’t have any issues with section 3.3. However, in the textboxes when I used the return key when there wasn’t already a line of text, it would mess up the left justification. So, I just left a dummy line of text at the bottom and added lines above it until I was done with that textbox - then deleted it.

I think that I have finally finished 3.2. I copied in the exercises that I had previously deleted. I think that I got them branded and coded in LaTex. It was the easier type of coding that I am beginning to get comfortable doing.

Question: Does Example 3 need the more advanced Latex coding?
Comment: In example 7, some of the arrays go outside of the example box.

The question and comment above would require the more advanced LaTex programming that I am not yet comfortable doing.

Example 3 looks ok - I’m not sure how we would
I think we can fix the overlap for the first time in example 7 by making the text in the first row two lines, for the second overlap I think we can take the third column as a whole and move it to the next line.

@emily.frank @kaitlin @jeusea
I’ve come across an issue when editing headers. In Chapter 1, sometimes when I would make certain headers “Heading 1,” all "" would be deleted, which messed up the LaTex coding. I was able to restore old versions and make it work eventually, but I’m coming across a similar issue in Chapter 3. In Chapter 3, all “<” seem to disappear when anything is updated to Heading 1. I can’t seem to find a way around the problem in this chapter. I tried restoring an old version and changing the headers like I did in Chapter 1, but that isn’t working. Any other heading number seems to work with no issues. Any suggestions on how to change Heading 1’s without messing up the LaTex coding? I know Jared did Chapter 2, and everything works fine. I also didn’t have issues with Section 1.4.

@kellis1 @tspahn @rbroussard3
Watch out for this issue if you make changes to the headers. For now, I’m skipping the heading edits until we can find a solution.

Hi @ashley.segalla , I just took a look and was not able to reproduce the issue. I was able to change all of the H3 in 3.1 and 3.2 to H1 using the Visual editor (highlight the heading, selecting the dropdown in the WYSIWYG editor and selecting “Heading 1”). Could you take a look and let me know if anything seems off? I saved the HTML from each section in a text file before editing just in case there is an issue and restoring doesn’t work.

Hey @elizabeth.kelly , thank you for checking! It looks like all the < symbols are missing in 3.1 and 3.2. Every other inequality symbol is there, with the exception of <. This is the same problem I was having.

@elizabeth.kelly In Chapter 4, it looks like a lot of the \ are getting deleted from the LaTex coding. When you make something Heading 1, you’ll see an error with the LaTex coding when you view the page.

@ashley.segalla thank you, I see it now! I just emailed Pressbooks; I’ll let you know what they say. Agreed that waiting to change any headings to H1 for the time being is a good idea until we figure this out.

I just went into 3.2 and was going to fix the < (less than symbol) issue that resulted from adding the Heading 1 stuff. I figured that it was just a question of adding the symbol back into the LaTex coding. That is not the case at all. Seems like it added a space before and after the < sign. Taking out the extra spaces did not fix the issue. Tried several other things, space on one side and not the other, using a \ before the symbol, etc. Nothing worked, so I left it as it was. Will be curious to see what Pressbooks says about it.

Hi all, Pressbooks response was:

“Sorry about this and thanks for this information. It’s very strange. I’ve replicated the problem in a test book and will bring it to the tech team. I haven’t been able to find a workaround that would support H1s with two-level TOC enabled in chapters with Latex equations with < in them, but I’ll write back once there are updates on this.”

So stay tuned…

Hi @elizabeth.kelly ! Jared found the solution to the missing < problem. By changing all “<” to “\lt” the signs are no longer disappearing. As far as the sections where some of the backslashes disappear, it seems to happen randomly as we edit the html coding. I can’t figure out what is making it happen, but it’s not necessarily when we change the headings. For that problem, restoring an older version and making the changes again seems to fix the problem.