已知x,y,z∈R,且x+y+z=8,x2+y2+z2=24求证:43
已知x,y,z∈R,且x+y+z=1,x2+y2+z2=3,则xyz的最大值是______.
已知:x2+y2+z2=xy+yz+zx,求证:x=y=z.
已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/
已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/(
已知x+y-z=0,2x-y-8z=0,且xyz不等于0,则x2+y2+z2/(xy+yz+zx)等于
x,y,z为正实数 求证 x2/(y2+z2+yz)+y2/(z2+x2+zx)+z2/(x2+y2+xy)>=1
(选做题)已知x2+3y2+4z2=2,求证:|x+3y+4z|≤4.
一道不等式的证明题,已知:(x2-1)(y2-1)(z2-1)=83 x,y,z>1求证:1/x+1/y+1/z≥1
已知x,y,z互不相等,且xyz不等于0,x2+yz=z2,y2+zx=x2,求证:z2+xy=y2
已知x2+y2+z2-2x+4y-6z+14=0,则x+y+z=______.
1.已知x2+y2+z2-2x+4y-6z+14=0,求x+y+z的值.
已知x2+4y2+z2-2x+4y-6z+11=0 求x+y+z的值