函数是数学课程中的核心知识,其观点和方法贯穿高中代数的全过程,同时应用于几何问题的解决。函数具有数和形的特征,从解析式出发可作纯粹的代数推理,从图像特征出发,可实现数与形的自然结合。一、由含参函数在给定区间上的零点个数求参数的取值范围 Function is the core knowledge of mathematics curriculum, its point of view and method runs through the whole process of high school algebra, at the same time applied to the solution of geometric problems. The function has the characteristics of number and shape, and can be used purely for algebraic reasoning based on the analytic formula. Starting from the image features, the function can combine natural numbers and shapes. First, the parametric range of the parameter is obtained from the number of zero points with the parameter in the given interval