Back to the book...

I’ve spent the last two days writing the parabolas section. My co-author is very vocal about his dislike of the Conic Sections which is why I’ve been able to get away with working on conics before sabbatical technically begins. The interested reader can see the book in progress here. The new trick I learned in writing this section was the use of the \rotatepath command. You can check out the slick results of using this command by using the hyperlink in the index of the book on “parabola, reflective property.” I have been gently reminded on occasion that I’ve yet to actually define what Conic Sections are, but I will eventually. For a SUPER COOL animation of Conics and other things mathematics, see Dr. Talman’s page. I actually e-mailed this guy with some of my Calc I animations, and he gave some good input.

In other news, has anyone else ever noticed that members of the Voltron Force wear the wrong color uniforms? Kieth wears red, but pilots the Black Lion; Sven wears black, but pilots the Blue Lion; Lance wears blue, but pilots the Red Lion. Hunk and Pidge wear the corresponding uniforms (orange-yellow and green, respectively.) I briefly took a stroll back to my early days and wrote down the permutation cycle which would restore the correct order, but realized that the Princess mucks it all up with her pink uniform later on in the first season.

Well, Taylor is anxious to plant the Chia Cat Grass her Uncle David and Aunt Tammy got her for Christmas. I plan to measure the growth and use it for a regression problem for my book. Yeah, math can take the fun out of anything! :-)

Merry Christmas!

Here’s hoping all of you had a Merry Christmas! I took a few days off writing “the book” and spent some time learning some math. Did you know that “sufficiently nice” vector fields can be resolved into a sum of a divergence-free field and a curl-free field? I didn’t. It’s call the Helmholtz Decomposition Theorem (also called the Fundamental Theorem of Vector Calculus.) It’s a very pretty result and has given me a new appreciation of all that stuff I teach in Chapter 15... It also has inspired me to write a pretty nifty take home assignment which I’m sure will surprise and delight my next class of Calc 3 students...

In other news, I found a free, on-line Complex Variables book here. The guy who wrote it is an honest-to-goodness topologist, which is why, I think, it’s so easy for me to read. I became overly curious about the Cauchy-Riemann equations - especially what they actually “meant” - and, once again, Wikipedia offered some interesting perspectives on the topic.

One of the great things about math is that there’s always more to know... and there’s so much good stuff out there! I’m just grateful that I can make a living doing this kind of thing!

The problem with computers...

It’s days like this I’m glad I don’t have a “real job.” Single digit overnight temperatures, dangerous wind chills, and who knows how many inches of snow... it was nice to observe all of this harsh weather from *inside* a warm house! A nice feature of a “Spring” sabbatical is that I won’t have to drive through any of Ohio’s “Spring” weather!

I spent the majority of my “book time” today trying to get LaTeX (pronounced lay-tek: that “X” is supposed to be the Greek letter “Chi”) to understand the concept of subdirectories (you’ll thank me later, Jeff!) The problem with computers is that they do exactly what you *tell* them to do - not necessarily what you *want* them to do. Getting LaTeX to do what you *want* it to do can be, well, time-consuming, frustrating, and tedious - but the end result is usually worth the effort; usually.

Let’s say you’re writing a book using LaTeX and you want to organize your files so that each chapter has its own subdirectory in which you store associated graphics files. When you go to compile the parent file in the main directory, LaTeX will not know where to look for all those graphics! It will either stop compiling and yell at you or just leave big, nondescript boxes labelled “#1”, “#2”, etc. Things were looking up when I discovered the \graphicspath{} command, but, alas, that only works for graphics specifically included using the \includegraphics{} command. Most of my graphics are generated using mfpic, and the \graphicspath{} command did nothing for these files. The solution? After some googling, I stumbled across this helpful page. I downloaded the import.sty and it fixed my problem! Now, I can keep all things Conics in my Conics folder and use the single command \import{./Conics/}{Conics} to let LaTeX know where all things Conics are located! There is one snag (of course!) You need to compile and METAPOST the chapter file in its own directory to make sure mfpic generates all the graphic files it needs before you import the chapter into the book. Such has always been my relationship with LaTeX.

In any case, I decided to give the distance and midpoint discussions their own section (and include an example that “requires” the graphing calculator) and found out a way to keep all the paragraphs from indenting; I never did like indenting paragraphs. The interested reader can find the newest revision here. You’ll also note that “comments” are now enabled on my blog, so post away!

Prelude to Sabbatical...

I’ve been on “Winter Break” a week and am already tired of relaxing. I’ve been sleeping, on average, 12 hours a day (this includes naps), eating way too much unhealthy food, and, the worst of it, watching countless hours of mindless television thanks to my new AT&T U-verse DVR. When I started to seriously consider adopting a 5th cat in an attempt to form a real-life Voltron, well, I decided it was time to start in on that College Algebra book. It has been my dream for years to write a College Algebra textbook which I can offer “at cost” to students. As technology has progressed, my ambition is to now offer, in addition, an electronic version embellished with hyperlinks to TeacherTube tutorials like these. My dear friend and colleague, Dr. Z, has co-ordinated his leave with mine and so we will hunt this “white whale” together. I finished my first section on the 17th. I’m not altogether happy with it, but it serves, I think, as a decent first draft. The interested reader can read the .pdf here.