分子=[x^(1/3)-1]^2分母=(x-1)^2={[x^(1/3)-1][x^(2/3)+x^(1/3)+1]}^2约分后，原极限=1/[x^(2/3)+x^(1/3)+1]^2 (x趋于1)=1/3^2=1/9
解如下图所示
