函数是一个重要的数学概念 ,二次函数是其极重要的一部分内容。它涉及的知识面宽 ,方法灵活 ,应用广泛 ,学生对其甚是头痛 ,一般不易掌握 ,教师教起来也很是费力 ,常常事倍功半。笔者在多年的教学实践中体会到 ,只有讲清并引导学生深刻理解了二次函数基本式的性质之后 ,学生的 The function is an important mathematical concept. The quadratic function is a very important part of it. It involves a wide range of knowledge, a flexible approach, a wide range of applications, students are even a headache to them, generally difficult to master, teachers are also very hard to teach, and often less effective. The author experienced in many years of teaching practice that only after clarifying and guiding the students to deeply understand the nature of the quadratic function, the students’