三次函数零点判别法

On the Test of Zero Vector of Cubic Function

三次函数是重要的初等函数之一,其性质是数学教学的研究重点。文章将根据其极值点的分布情况,应用韦达定理推导出三次函数零点的一种判别法,为解决三次函数零点个数及其相关问题提供了借鉴和参考。

Cubic function is one of important elementary functions and its properties are the focus of mathematics teaching. The paper deduces a test of zero vector of cubic function from Vieta’s theorem, based on the distributions of its extreme value points, which provides a reference basis for the number of zero vector and its related problems.