L'Hospital's rule......................................(edit)

When we were discussing limits of multivariable functions last week, why do you suppose that we never mentioned L'Hospital's rule?

and while we're on this topic, note that both of the single variable limits lim_{x->0} x/(x^2) and 
lim_{x->0} (x^2)/x are "=0/0", but one of these limits exists and the other one doesn't.  THIS MEANS THAT A LIMIT -->0/0 DOES NOT SPECIFY WHETHER THE LIMIT EXISTS OR NOT