二次根式是初中数学的重要内容之一,比较二次根式的大小也是中考和数学竞赛的常见题,具有很强的技巧性.为了帮助同学们掌握好这部分知识,本文归纳总结了比较二次根式大小的一些方法与技巧.一、外因内移法将根号外的因数移入根号内,转化为比较被开方数的大小. Secondary root is one of the important content of junior high school mathematics, comparing the size of the secondary root is also a common problem in the entrance exam and math competition, with a strong skill.To help students to master this part of the knowledge, this article summarizes the second Roots size of some of the methods and techniques. First, the external factor method will root outside the root number into the root number, converted to compare the size of the square root.