Answer
$d(C, D) = 1$
Work Step by Step
$d(C, D)$ represents the distance between the points C and D on a number line.
If the coordinates of C and D are $c$ and $d$, respectively, then:
$d(C, D) = |c-d|$
Based on the given number line, the coordinates of C and D are 0 and 1, respectively.
Use the formula above to obtain:
$d(C, D) = |0-1| = |-1| = 1$
Thus,
$d(C, D) = 1$
