Answer
It is a one-to-one function
Work Step by Step
$r(x) = 2 + \sqrt {x + 3}$
One to one if f(p) = f(q) and p = q
$f(p) = 2 + \sqrt {p + 3}$
$f(q) = 2 + \sqrt {q + 3}$
$ 2 + \sqrt {p + 3} = 2 + \sqrt {q + 3}$
$\sqrt {p + 3} = \sqrt {q + 3}$
$p+3 = q+ 3$
So p = q
Thus it is a one-to-one function
