设右焦点C则右焦点坐标为（1,0）设直线L的点斜式方程为y-0=2(x-1)与椭圆方程联立得Xa+Xb=5/3,XaXb=0在△OAB中,|AB|=((Xa-Xb)^2+(Ya-Yb)^2)^0.5化简得：|AB|=5/3*5^0.5O点到直线L距离为d=2/5^0.5则S△OAB=|AB|*d/2=5/...