回归定义的实质是重新审视概念,并用相应的概念解决问题,是一种朴素而又重要的思想方法。圆锥曲线的定义既是有关圆锥曲线问题的出发点,又是新知识、新思维的生长点。对于相关的圆锥曲线中的数学问题,若能根据已知条件,巧妙灵活应用定义,往往能达到化难为易、化繁为简、事半功倍的效果。 The essence of the definition of return is to re-examine the concept, and use the corresponding concept to solve the problem, which is a simple and important way of thinking. The definition of conic curve is not only the starting point about the conic curve problem, but also the growth point of new knowledge and new thinking. For mathematical problems related to the conic curve, if we can apply the definition cleverly and flexibly according to the known conditions, we can often achieve the effect of eliminating difficulties and simplifying things with less effort.