等式根号x-1=根号x+1*根号x-1有意义的条件
问题描述:
等式根号x-1=根号x+1*根号x-1有意义的条件
答
根号下(x²-1)=根号下(x+1)×根号下(x-1),则:
x²-1≥0且x+1≥0且x-1≥0
得:x≥1