Consider the function $f:\{1,2,3,4\} \to \{1,2,3,4\}$ given by $$f(n) = \twoline{1 \amp 2 \amp 3 \amp 4}{4 \amp 1 \amp 3 \amp 4} \text{.}$$

1. Find $f(1)\text{.}$
2. Find an element $n$ in the domain such that $f(n) = 1\text{.}$
3. Find an element $n$ of the domain such that $f(n) = n\text{.}$
4. Find an element of the codomain that is not in the range.