回復 1# thankyou 的帖子
第2題
\begin{align}
& \overline{OQ}=a,\overline{OR}=b \\
& {{a}^{2}}+{{b}^{2}}=36 \\
& P\left( \frac{2}{3}a,\frac{1}{3}b \right) \\
& OAPB=\Delta OBP+\Delta OAP=a+\frac{1}{3}b \\
& {{\left( a+\frac{1}{3}b \right)}^{2}}\le \left( {{a}^{2}}+{{b}^{2}} \right)\left[ {{1}^{2}}+{{\left( \frac{1}{3} \right)}^{2}} \right]=40 \\
& OAPB\le 2\sqrt{10} \\
\end{align}
