I've been playing around with Grapher today, that "little math app" that comes with Mac OS X. Up to now i already used it for 2d function plotting, but have never used it for the 3d vector stuff we do at school at the moment.

oh what a fool i was! it's just the parameters that look a little weird compared to what gets taught in my math class (brackets instead of braces, e.g.), and specifying parameters is something you have to see once... great that i find out now, when we're almost done with the topic :-/

enough of the talking - here is something useful, the 1st part of the homework we got over the weekend, finding the piercing points of a line and the coordinate planes that build up the R3 (E_x1x2, E_x2x3, E_x1x3) ("E" is the first letter of the german word for plane, in case you wonder..). During this task, you discover that the given line and one of the planes are parallel.. which confused me, but the only proof i could probably get was either the formula that just hinted me to the paralellism (which i questioned) or a plot... so i fired up grapher. this is what it looks like:


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If you have OS X and want to toss it around yourself a little, here is the gcx file for the above, and here is the first part of the second task. In the latter one you can still see the dots i used to build up the parametric form of the initially normalized equation. Please bear with me, i know the values suck, but at least it's the right result :)