lim(x→1)[x^(1/3) -1]/(√x -1)
=lim(x→1)[x^(1/3) -1][x^(2/3)+x^(1/3)+1](√x +1)/[x^(2/3)+x^(1/3)+1](√x -1)(√x +1)
=lim(x→1)(√x +1)/[x^(2/3)+x^(1/3)+1]
=(1+1)/1+1+1)=2/3[x^(2/3)是怎么写的哦是x-1=[x^(1/3)]³-1=[x^(1/3) -1][x^(2/3)+x^(1/3)+1] (立方差公式）x^(2/3)用笔写下来是怎么写的，是根号下多少x^(2/3表示x²开3次方