设x,y,z为实数,且3乘以的绝对值++^2=0,求x^2+y^2+z^2+2xy-2xz-2yz的值?
问题描述:
设x,y,z为实数,且3乘以的绝对值++
答
2x-1=0
9y^2-6y+1=0,(3y-1)^2=0
z-1=0
x=0.5
y=1/3
z=1
x^2+y^2+z^2+2xy-2xz-2yz=(z-x-y)^2=1/36