Answer
The value of $x$ such that the function $f\left( x \right)$ is undefined is $\underline{x=1,x=2}$.
Work Step by Step
From the graph, the value of the function is tending to $\infty $, which means that the function is undefined for $x=1$.
It is also observed that the function doesn’t attain any value at $x=2$.
Therefore, the function is undefined at $x=1\,\text{ and }\,x=2$.
