均值不等式是“不等式”这一章的重要内容之一 ,是求函数最值的一个重要工具 ,也是高考常考的一个重要知识点 .要能熟练地运用均值不等式求解一些函数的最值问题 .一、几个重要的均值不等式1 a2 +b2 ≥ 2ab ,ab≤ a2 +b22 ,其中a、b∈R ,当且仅当a=b时 ,“ =”号成立 ,2 .a+b≥ Means inequality is one of the important parts of the chapter “Inequality”, it is an important tool to find the most value of the function, and also an important knowledge point of the college entrance examination.It is proficient to use mean inequality to solve the most value problem of some functions. First, several important mean inequalities 1 a2 + b2 ≥ 2ab, ab ≤ a2 + b22, where a, b∈R, “=” is true and only if a = b, 2.a + b≥