一、两道试题试题1(江苏省镇江市2013届高三期末)已知椭圆O的中心在原点,长轴在x轴上,右顶点A(2,0)到右焦点的距离与它到右准线的距离之比为3~1/2/2,不过A点的动直线x-2y+2m=0交椭圆O于P,Q两点.(1)求椭圆的标准方程;(2)证明P,Q两点的横坐标的平方和为定值;(3)过点A,P,Q的动圆记为圆C,动圆C过不同于A的定点,请求出该 One or two test questions 1 (at the end of the third phase of the 2013 session of Zhenjiang City, Jiangsu Province) The center of the ellipse O is known at the origin, the long axis is on the x-axis, and the distance from the right vertex A(2,0) to the right focus is right to it The ratio of the alignment line distance is 3~1/2/2, but the moving line at point A is x-2y+2m=0 and the ellipse O is at P and Q. (1) The standard equation for the ellipse is obtained; (2) It is proved that the sum of the squares of the abscissas of the points P and Q is a fixed value; (3) The circle of the points A, P, and Q is recorded as a circle C, and the circle of motion C is different from the fixed point of A.