1. The problem statement, all variables and given/known data lim (x,y) -> (0,0) for: (x^3 - y^3) / (x2 + y2) 2. Relevant equations 3. The attempt at a solution I am checking all the possible lines to check what the limit would be if it did exist: y = mx, plug this into the equation above (x^3 - (mx)^3) / (x^2 + (mx)^2) reduces to: x(1 - m^3) / (1 + m^2) so, the limit of this when it approaches 0 would be 0 if it exists. Now how do I find out that it does exist? I was told to use the squeeze theorem, but I don't know how to find the bounds.