JLo's solution works for me! In general, a function that is differentiable in some direction at a point is continuous in that direction. It's a good thing that this in the "Tricks" section.
blackjack
<a href="http://c.casalemedia.com/c?s=51816&f=3&id=0" target="_blank"><img src="http://as.casalemedia.com/s?s=51816&u=http://perplexus.info&f=3&id=0&if=0" width="120" height="600" border="0"></a>
flooble's webmaster puzzle
re: Computer solution
