\(\lim\limits_{x\rightarrow3^+}\frac{\left|x-3\right|}{x-3}=\lim\limits_{x\rightarrow3^+}\frac{x-3}{x-3}=1\)
\(\lim\limits_{x\rightarrow3^-}\frac{\left|x-3\right|}{x-3}=\lim\limits_{x\rightarrow3^-}\frac{-\left(x-3\right)}{x-3}=-1\ne1\)
\(\Rightarrow\) Không tồn tại \(\lim\limits_{x\rightarrow3}\frac{\left|x-3\right|}{x-3}\)