When $x=2$, the arrow from $x=2$ on the domain axis to $f(x)=f(2)=\frac
12 (2) = 1$ on the target axis shows the function connection.
The
arrow pointing up on the target axis at $f(x)=1$ with length $\frac 12$
indicates that when $x=2$ the function $f$ is increasing at a rate of $\frac 12$
units of $y$ per unit of $x$ .