椭圆x^2/2+y^2=1及圆外一点M(0,2),过这点引直线与椭圆交于AB两点,求AB的中点P的轨迹方程

AB的中点P的轨迹方程是2(Y-5)^2+X^2=2.设过点M(0,2)的直线为y=kx+2,将y=kx+2代入椭圆方程x^2/2+y^2=1得(2k^2+1)x^2+8kx+6=0x2,x2是方程的根,则有x1+x2=8k/(2k^2+1)y1=kx1+2,y2=kx2+2设AB的中点P的坐标为P(X,Y),则X=(...