二次函数有丰富的内涵和外延。我们可以以它为代表来研究函数的性质,可以建立起函数、方程、不等式之间的联系,可以编拟出层出不穷、灵活多变的数学问题,考察学生的数学基础知识和综合数学素质,特别是能从解答的深入程度中,区分出学生运用数学知识和思想方法解决数学问题的能力。 Quadratic function has rich connotation and extension. We can use it as a representative to study the nature of the function, we can establish the relationship between function, equation, inequality, we can develop an endless stream of flexible mathematical problems, examine students’ basic knowledge of mathematics and comprehensive mathematical quality, especially It is able to distinguish the students’ abilities of using mathematical knowledge and method of thinking to solve mathematical problems from the depth of solution.