(-3)^(1/3)<0所以(-3)^(1/3)-2<0所以|(-3)^(1/3)-2|=-((-3)^(1/3)-2)=2-(-3)^(1/3)=2+3^(1/3)即2加3的立方根
－3的立方根减2的绝对值=-(3的立方根)-2=-(3的立方根+2)
－3的立方根减2就是正3的立方根加2
