Suppose we're given the function $$f(x)=\begin{cases}\displaystyle{x+2}&\text{if}\ 0 \le x \le 2\cr \displaystyle{5-x}&\text{if}\ 2 < x \le 8\end{cases}.$$

a) Evaluate the following.
i) $f(1)=$
ii) $f(4)=$
iii) $f(f(4))=$

b) What is the domain of $f(x)$?
Domain:

Hint: