已知xyz∈R+求证:(1+x²)(1+y²)(1+z²)≥8xyz
已知x.y.z属于R,求证:(1+x^2)(1+y^2)(1+z^2)大于等于8xyz
1、x³+x²y-x²z-xyz
已知xyz属于R+,x+y+z=1,求证x^3/(y(1-y))+y^3/(z(1-z))+z^3/(x(1-x))大于
已知x^2+y^2+z^2=1,求证x+y+z-2xyz
已知x,y,z都是正数,且xyz=1,求证:x^2/(y+z)+y^2/(x+z)+z^2/(x+y)≥3/2
xyz属于R+,且xyz=1求证:x的3次方/(1+y)(1+z)+y的3次方/(1+x)(1+z)+
3^x=4^y=6^z 求证1/z-1/x=1/zy 比较3x.4y 6z的大小 xyz∈R+
已知xyz均为正数,求证1.732/3(1/x+1/y+1/z)
xyz≠0,且x+y+z=0,求证根号(1/x²+1/y²+1/z²)=(1/x+1/y+
已知x+y+z=0,xyz=1,求证:x,y,z中必有一个大于2/3.
数学题已知xyz≠0,且x+y+z=1,x²+y²+z²=1,求1/x+1/y+1/z的值
已知x,y,z满足xyz=1,求证x^3/(x+y)+y^3/(y+z)+z^3/(z+x)大于等于3