算术平方根a(1/2)具有双重非负性,(1)是被开方数必须是非负数,即a≥0,(2)是算术平方根的值是非负数,即a(1/2)≥0。在许多关于算术平方根的题中,可利用这两个隐藏性质来解题。一、利用被开方数必须是非负数例1已知y=(x-1)(1/2)+5(1-x)(1/2)+2,求xy的值。 Arithmetic square root a (1/2) has a double non-negative, (1) is the square must be non-negative, that is a ≥ 0, (2) is the square root of the arithmetic value is non-negative, that is, 0. In many questions about the arithmetic square root, these two hidden properties can be used to solve the problem. First, the value of xy is found using the square root of the number of eqs., Which is nonnegative, given that y = (x-1) (1/2) +5 (1-x) (1/2) +2.