Let $a, b \;\epsilon \; R, (a ≠ 0). $ If the function f defined as $f(x) = \begin{cases} \frac{2x^2}{a}, & 0 \leq x < 1 \\ a , & 1 \leq x < \sqrt 2 \\ \frac{2b^2 - 4b}{x^3}, & \sqrt 2 \leq x < \infty \end{cases}$ is continuous in the interval $[0, ∞)$, then an ordered pair $(a, b)$ is