x^2+y^2+z^2=1,求yz/x+xz/y+xy/z最小值设m=y/x,y=mx,则m为正实数x^+m^x^+z^=1x^=(1-z^)/(m^+1)设k=yz/x+xz/y+xy/z,k为正实数,则k=mz+z/m+mx^/z=z(m+1/m)+m(1-z^)/(z(m^+1))kz=z^(m+1/m)+m/(m^+1)-mz^/(m^+1)z^(m+1/m...