Hi guys.

I have a problem, where there are 400 parabolas, each varying slightly, and a point marked on a map. I'd like to find which of these 400 parabolas has a point that gets the closest to the point I have marked.

At the moment I am running through each parabola with 0.05 time intervals between each step to find which parabola contains the closest point, it's not too slow, eating up 20ms at MAX on a Pentium 4M 2.2ghz, that's within x of 800 pixels and y of 5000 pixels.

What I was wondering, is if there is some sort of formula or 'trick' I can use to tell which of these parabolas would be the best choice without having to run through them all.

Thanks in advance.