**Example LF.1.2 **:$f(x)
=x+2$. "Added value": $2$

An arrow in the mapping diagram that starts at $x$ will end at
the point, $x+2$, two units above the position $x$ on the target
line.

**Motion Interpretation:** If $x$ is time and $f(x)$ is the
position of an object on the target axis at time $x$, then at time
$0$ the object is at position $2$. The position at time $x$ is is
precisely $x$ units above (below) $2$ when $x>0$
($x<0$). The object is moving at a velocity of $\frac {\text
{unit position}} {\text {unit time}}$.