That's so mathematically geeky, I love it. :lol:

Which reminds me of a little video (in Romanian) on a similar subject, where the bodyguards at the entry in a club don't allow people in unless they answer a Maths-related question. Two guys get it right, then a blonde comes along and she's asked "what's the square root of 4?" She says "6", bodyguards look at her and say "Close enough... get in." Then a more geeky-looking guy walks in, and what do they ask him? Lagrange's mean value theorem. He starts saying it, gets it right almost all the way, but then... f(b)-f(a)/(b-a) = f(c). The bodyguards ask him to say that bit again, he still says it.

One of the bodyguards says "You idiot, it's f'(c)!" and picks him up and throws him out of the club.