Answer
Refer to the explanation below.
Work Step by Step
Case : 1: If the function $f(x,y)$ is continuous at $ (a,b)$, then we get
$\lim\limits_{(x,y) \to (a,b) }f(x,y)=3$
Thus, when the function $f$ is continuous at $(a,b)$, the limit exists and is equal to $3$.
Case 2: If $f$ is not continuous at $(a,b)$ the limit may not be $3$ and may not exist.
