Find $\lim_{(x,y)\to(0,0)}\frac{(x^2-y)}{(4x^2+y^2)}$ using ε–δ definition of a limit I was wondering if anyone could help with this $\epsilon–\delta$ definition of a limit. I have looked it up in my calculus book and online and I just don't understand how to do it.
Prove, using the  $\epsilon–\delta$ definition of a limit that
$$\lim_{(x,y)\to(0,0)}\frac{(x^2-y)}{(4x^2+y^2)}$$

The limit doesn't exist since $$\lim_{t\to 0}f(t,0)=\frac{1}{4}$$ and $$\lim_{t\to 0^+}f(0,t)=-\infty .$$
