When I learn something, especially in calculus, I like to get some intuition on where things come from and why they work, thing is I can't quite fully understand why the jacobian works...I'm not looking for an explanation on how to do it, I already know that, I just want to know why it works, if someone can explain or show me somewhere that explains it that would be great. I am not looking for a rigorous proof, something remotely simple would be nice. I read http://planetmath.org/encyclopedia/JacobianAndChainRule.html" [Broken] and have been reading wikipedia, and I understand it a bit better now, but not fully. I don't really get the crossing part of it. Can someone help clear things up?