在大学自主招生考试中,不等式的证明占有很大的份量.面对复杂的不等式,正面直接求解有困难时,往往需要另辟蹊径,倘若观察题目条件,改变已知的形式,发现不等式与函数的本质联系,从函数角度去思考,利用函数的单调性、凸凹性,往往能起到柳暗花明又一树的的效果.本文就以2014年大学自主招生压轴题为例,说明构造函数,利用函数单调性、凸凹性,能给我们的解题带来意想不到的效 In the university entrance examination, the proof of inequality holds a great amount.When faced with complex inequalities, it is often necessary to find another way to solve the problem of positive direct solution.If we observe the conditions of the topic and change the known form, we find that the inequality and the nature of the function Contact, from a functional point of view, the use of monotonicity, convexity and conciseness of the function, often can play a brilliant future tree effect.This article takes 2014 college self-enrollment finale as an example, illustrates the constructor, the use of monotonic function , Convexity and convexity, can bring unexpected effect to our problem solving