高中数学教材中提到椭圆、双曲线和抛物线都称为圆锥曲线,这是因为这三种曲线都可用一个平面与圆锥面相截,所得的截口线即为这三种曲线之一.这个结论用高等数学的知识是不难证明的,但较少看到此结论的初等证明.本文拟探究此结论的初等证明方法.设圆锥面的半顶角为β,为了便于研 The high school mathematics textbook mentioned that ellipses, hyperbolas, and parabolas are called conic curves. This is because these three types of curves can be cut by a plane and a conical surface. The resulting cut line is one of the three curves. The use of higher mathematics knowledge is not difficult to prove, but less to see the initial proof of this conclusion. This article is intended to explore the initial proof of this conclusion. Set the semi-apex angle of the conical surface is β, in order to facilitate the study