Sorry. I didn't have the time, nor some "real" idea's on what to write.

Matrix multiplication is allready covered extensively a previous issue and more examples are abundantly available online. I also think that the harder concepts in linear algebra are harder to understand and less usefull to a gamedevelopment community. Quaternions could be interesting, but I would need to study them myself first.

Another problem is, that I haven't touched pascal for some time now. I'm actually messing with AVR's, C and my soldering iron.
Therefore, I don't really know what to write about.