Answer
$\sqrt0,\sqrt1,\sqrt4,\sqrt9$
Work Step by Step
A number $\sqrt a$ is rational if there is a rational number $b$ so that $b^2=a$.
We have:
$\sqrt 0=0$ because $0^2=0$
$\sqrt 1=1$ because $1^2=1$
$\sqrt 4=2$ because $2^2=4$
$\sqrt 9=3$ because $3^2=9$
So the rational numbers are:
$$\sqrt0,\sqrt1,\sqrt4,\sqrt9$$
