Answer
$a=0$ and $b=9$
Work Step by Step
We are given:
$0\lt 2x\lt 6$
We divide by $2$:
$\frac{0}{2}\lt \frac{2x}{2}\lt \frac{6}{2}$
$0\lt x\lt 3$
We take the square:
$0^{2}\lt x^{2}\lt 3^{2}$
$0\lt x^{2}\lt 9$
Therefore:
$a=0$ and $b=9$