Monthly Archives: October 2008

Testing LaTEX and Quartic Roots

This post is simply a test of the LaTEX plugin that I supposedly have installed on this blog.  I haven’t used it in conjunction with Windows Live Writer Beta, my preferred blog writing software.

Feel free to sing along to the tune of “Pop Goes the Weasel” as you read the quadratic formula below:

[tex]x = displaystyle frac{-bpm sqrt{b^2-4ac}}{2a} [/tex]

Speaking of which, I introduced my algebra students to the fact that there exist some rather lengthy formulas for solving cubic and quartic equations. In fact, the four roots of the quartic equation,

[tex]x^4 + ax^3 + bx^2 + cx + d= 0[/tex]

can be found in four individual equations over at Planet Math. I dare you to make your algebra students memorize those for the next exam.

Hours of Daylight Project

image In my math models course this term, my students have begun working on their projects.  They will complete 3 – 4 modeling projects throughout the semester.  We just completed work on a Highway Design Problem with some basic curve fitting techniques to join two or three different grades (slopes) of road sections using parabolic curves.

In the current project, three teams are developing a formula to calculate the number of hours of daylight that a given point (of latitude) receives for each day of the year.  I’ve introduced the problem and laid out some notation and assumptions to guide them along.  Here are some snapshots from the board on Monday.  The students asked that I document these notes since their copies did not do justice the concepts they were supposed to represent.

MathModelsDaylight 002    MathModelsDaylight 003

MathModelsDaylight 004    MathModelsDaylight 005

MathModelsDaylight 006    MathModelsDaylight 007

MathModelsDaylight 008    MathModelsDaylight 009

MathModelsDaylight 010    MathModelsDaylight 011

MathModelsDaylight 012

Excel Tip: Paste Picture Link

imageThis is a trick in Excel that will definitely come in handy.  I imagine a good many power users of Excel are familiar with this, but as it was new to me and pretty darn cool, I thought I’d share.

Situation: Working along in a spreadsheet and you have the format all set just they way you like it, columns and rows merged, widths perfectly adjusted and you want to insert a table of information.  What you could do is just re-align everything that you just spent hours, if not days, getting just so.  You could make new columns, new rows, adjusting everything.

New Solution: Create the table somewhere out of the way, either on another sheet in the workbook or somewhere way off to the side.  Then copy the region and paste it as a “Picture Link”. 

In Microsoft Excel 2007, after copying the desired region, on the Home tab of the ribbon, click the down arrow just below Paste and select As Picture > Paste Picture Link.

In Microsoft Excel 2003, copy as usual, then while holding shift, select Edit .. Paste Picture Link. 

Now you have an image that you can move around on the spreadsheet anywhere.  By using the Picture Link  you can also update the “out-of-the-way” table and it will update in this picture, as well.

By the way, there is a “Camera” tool in Excel that will also allow you to do the same thing.  Here’s a demo video of the Paste Picture Link tool.


HT: Joel (Father-in-law)

Extracting Broken Headphone Jack

Headphone Jack 002The HTC8125 (Wizard) brought another adventure (see previous adventure).  This time around the cradle that we use for charging managed to break off a piece inside the headphone jack.  This cradle is also a speaker so in addition to a charging plug, there is also a headphone plug that inserts into the phone.  Unfortunately, Lori (now the proud owner of my old smartphone) has had some difficulty docking the phone into the cradle.  Unbeknownst to her, the headphone plug broke this morning as she grabbed the phone and headed to Lubbock.

She realized there was a problem when the only sound the phone would make was when it rang.  It would not make any noises and she could not talk to anyone over the phone.  Luckily, she could still communicate with the world through text messaging, so I knew that she wasn’t laying in a ditch somewhere unable to speak when she called me.

We diagnosed the problem when she got home:

How to removed a broken headphone plug from the headphone jack?

Solution:  Cut a piece of a straw about 1 1/2 inches long, then cut it length wise in half.  It is important to note that the phone jack is not a standard headphone plug, but smaller so if you are attempting to use this technique to extract a plug in your mp3 player or other phone, you may need to use more of the straw than just half.  Also, if you use this technique, I take no responsibility for the outcome.  It worked for us, but try it at your own risk.

Now, roll up the straw and insert into the jack to protect the internal parts from the super glue.  Take a tooth pick and douse it in super glue and insert into the jack.  I actually tried this whole technique a couple of times and didn’t get it to work until I used a significant amount of super glue.  Once inserted, I allowed it to set and yanked it out.  Ouila!!

Headphone Jack 001      

EXTRACTED!!  Woohoo!  It now works like a charm.

Blog Posting from Word 2007

As I was preparing revisions to my University Life course schedule, I opened up Word 2007 and noticed something that I had not noticed before. When I was opening a new document there was an option to do a blog post. While I know that Microsoft has developed software for posting to various blog APIs, I did not recall this functionality being available in Word 2007. What interested me most about this is the ability of Word to handle the posting of images and equations.

On this blog, I have a LaTEX rendered which allows me to enter equations, even though it’s been a while since I’ve bothered to post anything much less something involving typesetting mathematics. So, in essence, besides pointing out the fact that the blogging capability exists in Word 2007, this post is to test image and equation posting from Word 2007.

I have been impressed with the new equation editor in Word 2007. It doesn’t reach the ease of use level (at least for me) of simply typing the LaTEX syntax, but it is quicker than in older versions of Word. It’s quicker because I use the keyboard for almost everything and I can just access “most” of the features I need straight from the keyboard quickly and easily, without having to remember a ton of keyboard shortcuts.

Just for kicks, here are a few samples:

UPDATE: Apparently these equations did not get posted either as images or anything else…. (10/13/08)

And here is a random picture that is on my hard drive and I have no idea why. A little formatting was added in Word 2007. It seems that this is not as useful as the picture insert tool in Windows Live Writer, since I am unable to simply link to a source picture and insert thumbnail. I only appear to be able to insert the picture as a whole.

UPDATE: Formatting carried through as expected. That’s a good thing.