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问题: 一道二次根式题目

麻烦写下详细过程,小弟化简不了啊

解答:

(1/x-1)^2÷[(1-x^2)/x^3]=
[(1-x)/x]^2÷[(1-x^2)/x^3]=
[(1-x)^2/x^2]÷[(1-x)(1+x)/x^3]=
[(1-x)^2/x^2]×[x^3/(1-x)(1+x)]=
[(1-x)]×[x/(1+x)]=
[x(1-x)]/(1+x)
x=√2-1
∴原式=[x(1-x)]/(1+x)=[(√2-1)(2-√2)]/√2
=(3√2-4)/√2
=3-4/√2
=3-2√2