I have the function $$f(x,y)={1\over{y-x^2}}$$ And it is very obvious that this is not continuous when $x=0\;\;y=0\;\;\;and\;\;\;x=1\;\;y=1$ but I'm having trouble remembering how to express this in set notation form. I'm wondering if it is obvious to anyone else.
Here is what I have: $$D: \left.\right\lbrace {(x,y)|(x,y)\neq(0,0),\;(x,y)\neq(1,1)} \left.\right\rbrace$$
I'm not used to these two variable functions yet.
Thanks for any help!