一次二次函数是重要的,学生对其解法已有较为全面、系统、深刻的认识,并在某些方面具备了把握规律的能力.然而,对三次函数问题,所使用的初等方法均需极强的技巧性,令学生难以把握.目前,研究函数性质的高等工具——导数,已进入中学课堂,在导数背景下再 A quadratic function is important, students have a more comprehensive, systematic, and profound understanding of their solution, and in some ways have the ability to grasp the law. However, for the cubic function problem, the primary method used Strong technical skills make it difficult for students to grasp. At present, the high-tech tool for studying the nature of the function, the derivative, has entered the middle school classroom and is in the context of the derivative.