已知xyz满足x+y-z=1,x-5y+2z=16,3y+z=5a,试确定a取什么整数时,可以使w=x2+y2+z2取得
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/(
已知实数x,y,z满足以下条件,求x的取值范围.x+y+z=a,x2+y2+z2=1/2 a2
已知xyz=1,x+y+z=2,x2+y2+z2=16,求1/x+y+1/y+z+1/x+z
已知a>0,实数x,y,z满足x+y+z=a,x2+y2+z2=a2/2,求x的取值范围
若实数x,y,z满足x+2y+3z=a( a为常数 ),则x2 + y2 + z2的取值范围是
已知xyz=1,x+y+z=2,x2+y2+z2=16,求代数式1xy+2z+1yz+2x+1zx+2y
已知非负实数x,y,z,w满足x2+y2+z2+w2+x+2y+3z+4w=17/2,那么x+y+z+w的最大值与最小值
若实数x,y,z满足x+2y+3z=a(a为常数),则x2+y2+z2的最小值为______.
已知x,y,z∈R,且x+y+z=1,x2+y2+z2=3,则xyz的最大值是______.
已知X,Y,Z是实数,且X2+Y2+Z2=3,X+Y+Z=1,则XYZ最大值是
求方程xyz + x2 + y2 + z2 = 2 确定的函数z = z( x,y)在点(1,0,-1)处的全微分dz,