根据题意得:
X-3=0,
Y+1=0,
X=0,
解得:X=3,Y=-1,Z=0,
∴X^2+Y^2+Z^2-XY-YZ-ZX
=9+1+0+3-0-0=13,
1/2[(X-Y)^2+(Y-Z)^2+(Z-X)^2]
=1/2[16+1+9]
=1/2×26
=13,
猜想:
X^2+Y^2+Z^2-XY-YZ-ZX=1/2[(X-Y)^2+(Y-Z)^2+(Z-X)^2].
根据题意得:
X-3=0,
Y+1=0,
X=0,
解得:X=3,Y=-1,Z=0,
∴X^2+Y^2+Z^2-XY-YZ-ZX
=9+1+0+3-0-0=13,
1/2[(X-Y)^2+(Y-Z)^2+(Z-X)^2]
=1/2[16+1+9]
=1/2×26
=13,
猜想:
X^2+Y^2+Z^2-XY-YZ-ZX=1/2[(X-Y)^2+(Y-Z)^2+(Z-X)^2].