函数值域是高中数学的难点.这是因为它没有固定的方法和模式,大部分值域问题与函数的最值问题密切相关,解决这类问题既涉及到一些具体的解题方法,又涉及一些抽象的逻辑方法,所以难以找到最佳的思维定势.这里仅就求以解析式给出的函数y=f(x)的值域的几种常用方法概述如下.1直接 Function range is a difficulty in high school mathematics. This is because it has no fixed methods and modes. Most value range problems are closely related to the function’s maximum value. Solving such problems involves both specific problem solving methods and Some abstract logic methods, so it is difficult to find the best mindset. Here are just a few common methods for obtaining the value range of the function y=f(x) given analytically as follows.