a^3+b^3+c^3+1/(abc)=a^3+b^3+c^3+3/(3abc)=a^3+b^3+c^3+1/(3abc)+1/(3abc)+1/(3abc)>=6（a^3*b^3*c^3*1/3abc*1/3abc*1/3abc）^(1/6)=6*(1/27)^(1/6)=6*根号(1/3)=2根号3取最小值的条件为a=b=c=1/(3abc)...