基本不等式是高中数学重点内容,是高考命题的热点,其基本形式为a+b/2≥(ab)~(1/2)(a>0,b>0)当且仅当a=b时取等号.在求函数最值问题时应用较广泛,但有些同学在运用基本不等式求最值时经常出错,究其原因是没有理清以下几点:(1)表达式中含变量的项均为正;(2)表达式中含变量的项之和或积为定值;(3)表达式中含变量的项可以相等,简称“一正,二定, Basic inequality is the key content of high school mathematics and is the hot topic of college entrance examination proposition. Its basic form is a + b / 2≥ (ab) ~ (1/2) (a> 0, b> 0) Take the equal sign.When seeking the most value of the function, it is widely used, but some students often make mistakes when they use the basic inequality to find the most value. The reason is that the following points are not clarified: (1) Are positive; (2) the expression of variables with the sum of the product or a fixed value; (3) expressions with variables can be equal, referred to as ”a positive, two fixed,