Solution
= Solution
The defining equation gives $y^2=2-(2/3)x^2\leq2$. Equality is attainable at $x=0$, with the positive branch giving
$$
\boxed{y_{\max}=\sqrt2\quad\text{at }(0,\sqrt2).}
$$
= Solution
The defining equation gives $y^2=2-(2/3)x^2\leq2$. Equality is attainable at $x=0$, with the positive branch giving
$$
\boxed{y_{\max}=\sqrt2\quad\text{at }(0,\sqrt2).}
$$