a名字叫a的算术平方根,它有两个“非负数”的性质,即被开方数a非负(a≥0),整个式子的值非负(a≥0),常称为算术平方根的“双非负性”.与绝对值|a|、偶次方a2n(为正整数),是初中阶段常用的三类非负数.运用他们可以设计不同的题目,但条件都较隐蔽,思维出发点较单一,只要你“看得起 A name of the arithmetic square root of a, it has two “non-negative” nature, that is the square root of a non-negative (a ≥ 0), the value of the entire formula non-negative (a ≥ 0), often called arithmetic Square root of the “double non-negative.” With the absolute value | a |, even-even a2n (positive integer), junior high school stage is commonly used in three categories of non-negative.Using them to design different topics, but the conditions are more subtle, Think of a more simple starting point, as long as you "afford to watch