In order to investigate the current debate about knowing and understanding sparked by David Didau's

post, I want to examine one small part of mathematics, which I happen to be teaching to a Higher maths class at the moment: finding the point which divides a line segment in a given ratio.

One way to approach this is to teach a formula:

The position vector of P, where P divides AB in the ratio m:n, is given by

**p**=(n

**a+**m

**b**)/(m+n)

If you know

how to convert a position vector to a coordinatethe convention that capital letters represents points and bold lower case letters represent corresponding position vectorshow to multiply or divide a vector by a scalarhow to add vectors together
then can probably now solve a problem such as:

Given that the point P divides S(3,4,-1) and T(5,8,11) in the ratio 3:1, find P.

At this point, a student knows how to find a point which divides a line segment in a given ratio. They may have no idea why this rule works. They may have no idea what a position vector …

Hello. This is pretty cool, how would someone like me go about doing that? SJ

ReplyDeleteLatex and funky.... in the same post?! ;-)

ReplyDeleteHmm... it does rather stretch the meaning of "funky" doesn't it?

ReplyDeleteThe plugin is here:

http://www.anlak.com/?page_id=66

To make it work I had to comment out the require Snoopy line in the plugin script.

Hi Jonesieboy. Looks great but is snoopy not a black and white dog (Translated: you lost me when you started talking about snoopy lines in plugin scripts). We need to have a serious chat at some point so you can bring me up to speed.

ReplyDeleteCheers dude

I like the sound of latex!

Hi Craig. I'm talking to David Gilmour about setting this up for exc-el blogs. Getting it working for comments may be a bit trickier. Meanwhile, you'll be wanting to mug up on LaTEX markup - here's a good place to start:

ReplyDeletehttp://www.forkosh.com/mimetextutorial.html

Unfortunately it doesn't work in comment - hey I just fixed it so it does! Man, being a geek is

souseful![tex]e^x=\sum_{n=0}^\infty\frac{x^n}{n!}[/tex]

Thanks for the link Robert. Very Useful. I'm just getting into my laTEX and it's time for bed unfortunately. See you tomorrow.

ReplyDelete[...] http://www.jonesieboy.co.uk/blog/2006/11/21/maths-formula-test/#comments [...]

ReplyDeleteAccording to the typographical pedants who wrote the specification, it should be typed as [tex]\LaTeX [/tex] or LaTeX in ordinary text. Nice though

ReplyDeletePhew - I've finally found out why plus signs were getting chomped - it was to do with the fancy comment posting done by this theme - 3K2. Once I disabled it, everything worked fine. As a final test:

ReplyDelete[tex]\frac{5x^2+3x+2}{7x^3+4}[/tex]