论文部分内容阅读
形如(a2)~(1/2)的化简是二次根式的重点内容,在历年中考中都有所体现.解答这类问题的关键就是要确定根号内开得尽方的因数(或因式)的底数的符号,然后利用公式:((a2)~(1/2))=|a|=(?)进行化简.下面就近几年全国各地中考中出现的这类问题作一个归纳,供大家参考.一、直接给出字母的取值范围例1当x<1时,化简(x2-2x+1)~(14/2)=______。解:∵x<1,∴x-1<0∴(x2-2x+1)~(1/2)=((x+1)2)~(1/2)=|x-1|=-(x-1)=-x+1注:在运用公式时,应先写成绝对值,再化简,这样可避免错误.
The simplification of form (a2)~(1/2) is the key content of the secondary roots, and it has been reflected in the annual examinations. The key to answering these questions is to determine the factors that have been developed within the root number ( The sign of the base of the factor or factor, and then use the formula: ((a2)~(1/2))=|a|=(?) to simplify. Here are some of the issues that have arisen in the national examinations in recent years across the country. A summary, for your reference. First, give the value of the range of letters directly Example 1 When x <1, simplify (x2-2x +1) ~ (14/2) = ______. Solution: ∵x<1, ∴x-1<0∴(x2-2x+1)~(1/2)=((x+1)2)~(1/2)=|x-1|=- (x-1)=-x+1 Note: When using a formula, it should be written as an absolute value and then simplified to avoid errors.