题目已知圆O:x~2+y~2=8交x轴于A,B两点,曲线C是以AB为长轴,直线l:x=-4为准线的椭圆.(1)求椭圆C的标准方程;(2)若M是直线l上的任意一点,以OM为直径的圆K与圆O相交于P,Q两点,求证:直线PQ必过定点E,并求出E的坐标;(3)如图1所示,若直线PQ与椭圆C交于 The problem is that the circle O: x ~ 2 + y ~ 2 = 8 intersect the x axis at A and B points, and the curve C is an ellipse with the major axis AB and the straight line l: x = Find the standard equation of elliptic C; (2) If M is any point on the straight line l, the circle K with OM as the diameter intersects the circle O at P and Q. Prove that the straight line PQ must pass the fixed point E, E coordinates; (3) As shown in Figure 1, if the line PQ and elliptic C intersection