2022 THREE(b)

The graph below shows the function $y=f(x)$.

For the function above:
(i) Find the value(s) of $x$ where $f(x)$ is not differentiable.

(ii) Find the value(s) of $x$ for which $f^{\prime }(x)=0$.

(iii) What is the value of $\underset{x\to -4}{\lim }f(x)$?
(State clearly if the value does not exist.)