Let's take the limit x→∞lim(x2−y2) Let's divide numerator and denominator by x^2: x→∞lim(x2−y2) = x→∞lim(x211−x2y2) Do Replacement u=x1 then x→∞lim(x211−x2y2)=u→0+lim(u2−u2y2+1) = 0−02y2+1=∞
The final answer: x→∞lim(x2−y2)=∞
Lopital's rule
There is no sense to apply Lopital's rule to this function since there is no indeterminateness of 0/0 or oo/oo type