Section), also known as conic section, conic section and conic curve, are some curves obtained by cutting a cone flat (strictly speaking, a right conical surface is completely tangent to a plane) in mathematics and geometry. About 200 years ago, people named and studied conic curves, and their discoverer was the ancient Greek mathematician apollonius.

Perga, 262 BC ~ 65438 BC+090 BC), at that time, apollonius had made a systematic study on their properties.

It is well known that conic curves are ellipses. This happens when the intersection between a cone and a plane is a closed curve. At this time, the plane is perpendicular to the axis of the cone. If the plane is parallel to the generatrix of the cone,

Straight line), conic curve is called parabola. Finally, if the intersection line is an open curve and the plane is not parallel to the generatrix of the conic, then the conic is a hyperbola. (In this case, the plane will intersect with two parts of the conic to generate two separate curves, although one of them is often ignored. )