问题引出从平面上一点P作圆C的切线,可能的切线条数为:点P在圆C内部时0条;点P在圆C上时1条;点P在圆C外部时2条.对于其他的圆锥曲线,有什么样的结论呢?类比猜测1.从平面上一点P作椭圆C的切线,可能的切线条数为:点P在椭圆C内部(含焦点的区域)时0条; The problem leads to a tangent to the circle C from a point P on the plane. The possible number of cuts is: 0 points for point P inside circle C; 1 point for point P on circle C; 2 points for point P outside circle C. For other conic curves, what kind of conclusion? Analog guess 1. From a point on the plane for the tangent of the ellipse C, the possible number of cuts: Point P inside the ellipse C (including the focus area) 0 ;