dpk’s weblog

An educational update:

I finished spring quarter with some good grades, bringing my credit total to 20: 10 credits of math, 5 of English, and 5 of philosophy. I decided to take it easy in the summer quarter, and am taking two online classes, which means I am home for dinner every night (a big plus!).

One of the classes is beginning programming (CSC 110, JavaScript). I’ve been programming since I was a kid, so the JavaScript class is straightforward (although I have caught myself making big mistakes..). In order to complete an AS degree, I have to have at least 5 CSC credits, and “unfortunately” they do not allow you to test out. I put unfortunately in quotes because it’s actually pretty nice to take it a bit easier, and because it means I’ll be earning at least 10 CSC credits, which will probably look better should I transfer to a 4 year school some day. I am taking the opportunity to update my knowledge of XHTML, and just generally reinforce good coding practices.

The other class is introduction to logic (PHIL 106) and is pretty interesting. I’m learning how to read and comprehend arguments presented as symbols, and how to identify valid and invalid arguments. By taking this class relatively early on, I hope to use the skills in later classes, to ensure what I write is at least valid if not correct.

I wasn’t entirely sure that I was going to complete a degree when I first decided to take some classes. If I had not received good grades in the first quarter, I think it’s fair to say I would have stopped right then. Now I feel pretty sure that I am going to complete a 2 year degree, and I might do it in exactly 2 years. I was feeling ambitious, and registered for three classes in the fall: Java programming (CSC 142, online), calculus I (MATH &151), and sociology (SOC 101, online). If I finish all three, that’ll bring me to a total of 45 credits in my first year. Woo.

The break between Summer and Fall quarters is the longest of them all. This year, Summer ended August 14th, and Fall began September 22nd. That coupled with the fact that both courses I took for the Summer were online led me to forget a whole lot about scheduling time for classes, or what you should have in your backpack in order to attend class. For example, a pencil. And paper. And the specific schedule showing what dates and times you should be in class. (A required class to take alongside Calculus is CSC 102Q, a 1 credit “how to use Mathematica” course. The class doesn’t start at the same time, however, so I was a week early.)

I think the Microeconomics class is going to be the toughest, by far. (I switched from SOC to ECON to fulfill a minor degree requirement.) The teacher has made it clear that he wants to hear no student opinions, only pure economic statements. The required literature is filled with opinions and facts that are not (and perhaps can not be) backed up. As the teacher is a contributor to the book, I am not exactly sure what to expect. Probably a few low grades on homework as I get in to my groove. Another factor concerning me is that the students have been split in to two groups for some assignments. From what I am told and have read, working in groups in school is a sure path to failure. Either some participants contribute nothing, ever, or those that claim parts of the project back out at the last minute without a word, or what they do bring to the table is insufficient. I’m hoping this is just overblown and that things will go smoothly.

I expect that the Java class will go pretty smooth. It will give me a chance to delve deep in to object oriented programming. Most of the development I’ve done lately is in PHP4, which as you may know is one of the least strict languages out there. It supports OO concepts, but because you don’t have to use them, it ends up feeling like “too much” structure for many projects. And I admit, I am kind of lazy at times. (Although I am pretty proud of a OO-structured library I wrote a month or two back, that someone else was able to extend later. Woo.)

Calculus is going to be review for the first week or two. I’m definitely looking forward to this class: I hope to be able to apply what I learn here, somehow, to the numbers I work with every day. Even if they don’t end up making any more sense than they do now. (Statistics might be a more appropriate class to take.)

So I’m taking a math class (pre-calc), mostly as a way to try to feel less dumb in my day-to-day life. I’m doing OK at it, getting most of the “higher” principles such as using conjugates to decomplexificate* a complex ratio. But I’m having trouble remembering some of the basics, especially during quizzes.

Historically, I’ve done better on quizzes than on homework, but now that I’m old, things have changed. Now I watch as other students finish their quizzes before I’m half way done with mine, and I still get things wrong.

I titled this post “math shame” because I hope that by sharing my shame, I will remember what I typed here, and will get it right the next time. Today’s inspiration is due to the fact that on a quiz, I forgot how to change √-2 into something that follows the “a + bi” form. I wrote 2i. The real answer, as pointed out by another student on our way out of class, is actually i√2. D’oh. If I had thought about √-4, I might have realized that’s really what 2i is.

I think this plan may work. There’s only two remaining class periods before the final, so I’ve got to get this shit down quick.

* Firefox says that’s not a word. Too bad.

I think I am missing that bone in the brain that allows you to prove trigonometric identities. I just got done with the first half of a final, and I totally botched one of the questions, which was “Prove tan (pi / 4 + x) = (1 + sin2x) / cos2x”. I got as far as changing the left side to (cosx + sinx) / (cosx – sinx), but then I got stuck. Wasted a full sheet of paper trying different ways to solve it.

What really gets me is I know we’ve done this problem (or something similar) a couple of times before, but I’ve been unable to figure it out each time. I know all of the standard identities and half-angle/double-angle/addition/subtraction equations but I can’t make them work here. It’s probably something completely obvious, too.

Update: Yeah. It was obvious.

• tan (pi / 4 + x) = (tan (pi / 4) + tan (x)) / (1 – tan (pi / 4) tan (x))
• tan (pi / 4) = 1, so (1 + tan (x)) / (1 – tan (x))
• Multiply by cos (x) / cos (x): (cos (x) + sin (x)) / (cos (x) – sin (x))
• Multiply by the (cos (x) + sin (x)) / (cos (x) + sin (x))): (cos^2 (x) + 2 sin (x) cos (x) + sin^2 (x)) / (cos^2 (x) – sin^2 (x))
• cos^2 (x) + sin^2 (x) = 1, 2 sin(x) cos (x) = sin (2x), cos^2 (x) – sin^2 (x) = cos (2x), so:
• Finally we have LHS (1 + sin (2x)) / cos (2x), same as RHS.

All I needed was a few days to ruminate over it. Bah.