All,

I've attached a sample Metapost file that generates some figures I needed
for my latest calculus exam.

One file I use a lot is a little function grapher I wrote in Metapost. I
wrote it so that you just have to change the clipping window and the
function definition. Afterwards, I have to change some labels manually, but
that doesn't take much time. It's pretty good with continuous functions,
but discontinuous functions, like (x+1)/(x-1) have to be drawn in pieces. I
am not a good enough programmer to figure out how to write code to take
care of curves with discontinuities. See beginfig(4);...endfig; for an
example of what I am talking about here.