What color hat am I wearing?   ...   random thoughts , logic , math
tue 2005-may-10 15:07:22 pdt   ...   permalink

I recently wrote up (in an email to someone) a few of my favorite cute little logic-ish puzzles, involving guessing the color of the hat on one's head. As long as I'd already written them up anyway, I figured I'd post them here so that others may share the joy. I did not invent them, and I have no idea where the first two come from; the third I provide a reference for below.

( colored hat problems )

Bezier curves   ...   what i learned today , math , cabri
wed 2005-jan-19 20:30:37 pst   ...   permalink

Yesterday I learned the math behind Bezier curves. Ever since I first started playing with a vector graphics program (probably MacDraw or SuperPaint, way back in the day), I always wondered what they were, and how those little handles manipulate the shape of the curve. Turns out the math is pretty cool.

Of course there's a whole lot of algrebra surrounding it -- basically, they're piecewise cubic polynomials. But what's most interesting is the meaning of those little handles in the drawing programs. In particular, there turns out to be this really elegant geometric construction.

( the construction )