怎样用好均值不等式

• 作 者: 曾安雄
• 机 构: 浙江泰顺县第一中学 325500
• 出 处: 中学生数学
• 发表日期: 2002年19期
• 关键词: 均值不等式 通项 函数解析式 正四棱锥 当且仅当 解题过程 钢锭浇铸 张思明 换元 可石

均值不等式是不等式中的重要内容,也是历年高考重点考查的知识点之一.对于二、三元均值不等式的应用,在平时学习中应引起重视. 一、直接运用是指找准切入点,直接套用二、三元均值不等式. 例1 若实数a、b满足a+b=2,则3a+3b的最小值是( ). (2001年春季高考题) (A)18 (B)6 (c)2√3 (D)2(?)

The mean inequality is an important part of the inequality, and it is also one of the key points of the college entrance examination in the calendar year. For the application of the two and three-way mean inequality, it should be paid attention to in the usual learning. First, the direct use means to identify the entry point, directly Applying a two- and three-ary mean inequality. Example 1 If the real numbers a and b satisfy a+b=2, then the minimum value of 3a+3b is (). (Spring 2001 college entrance examination question) (A)18 (B)6 (c )2√3 (D)2(?)