基本不等式ab(1/2) ≤(a+b)/2(a≥0,b≥0)的应用是高考的重点内容也是热点内容,我们要给予足够的重视,对利用基本不等式求最值的题目,方法较多,题型较多,灵活性强,涉及面广,有一定难度.因此,我们要掌握基本题型与方法,善于归纳解题规律,熟悉必要的解题技巧.本文对一道典型题目进行了多角度变式,探究了“1”的代换在基本不等式求最值中的应用技巧.典型例题已知a>0,b>0,a+2b=1,求 The basic inequality ab (1/2) ≤ (a + b) / 2 (a ≥ 0, b ≥ 0) is the key content of the entrance exam is also hot content, we should pay enough attention to the use of basic inequalities to find the value Therefore, we should master the basic questions and methods, be good at inducting the law of solving problems and be familiar with the necessary solving skills. A typical problem is a multi-angle variation, exploring the application of “1 ” substitution in finding the most value of the basic inequality. A typical example known a> 0, b> 0, a + 2b = 1,