Mathematics - Application of Derivative Question with Solution | TestHub

If the other edges are $a,b$, the space diagonal condition gives $a^2+b^2+2=8$, so $a^2+b^2=6$. Hence $ab\le 3$, with equality at $a=b=\sqrt{3}$. Thus $V_{\text{max }}=3\sqrt{2}$ and $V/\sqrt{2}=3.00$.