Peach Co’s latest results are as follows: In addition, extracts from its latest statement of financial position are as follows: What is Peach Co’s return on capital employed (ROCE)?
【简答题】已知椭圆C的方程为 x 2 a 2 + y 2 b 2 =1 (a>b>0),称圆心在坐标原点O,半径为 a 2 + b 2 的圆为椭圆C的“伴随圆”,椭圆C的短轴长为2,离心率为 6 3 . (Ⅰ)求椭圆C及其“伴随圆”的方程; (Ⅱ)若直线l与椭圆C交于A,B两点,与其“伴随圆”交于C,D两点,当|CD|= 13 时,求△AOB面积的最大值.