Actually, this is a mathematical principle. For example, the tangent in an ellipse is the same as that in a hyperbola, and its Ali is amazing and special. Actually, like magic, it is expressed in another way.

For example, a similar tangent equation is the same in an ellipse, a hyperbola of XXX0/A square +yy0/b square = 1, and even a parabola is no exception. If you bring in some points, you will get the answer.

Just feel it slowly.