《中小学数学》(初中版)2011年3月刊载了王发岳的《关于复合二次根式的化简》,笔者研读以后,对文中介绍的复合二次根式化简的三种方法:凑方法、待定系数法和公式法表示赞同,但对“待定系数法”中表示分析的一句话持不同意见.一个二重复合二次根式可以化简成简单二次根式,它的被开方数一定是一个完全平方式,否则上述化简不可能.对这种复合二重根式的化简,“凑方法” “Junior high school mathematics” (junior high school edition) published in March 2011, Wang fat “on the reduction of compound secondary root”, the author study, the article introduced three methods of compound second radicalization: Minato method, To be determined coefficient method and formula law agree, but “Pending coefficient method ” express a different opinion expressed in the sentence .A double compound quadratic root can be simplified into a simple quadratic root, its square root Must be a completely flat style, otherwise the above simplification is impossible .To this complex double radical reduction, “Minato ”