Question

If x=997 y=998 z=999 then the value of x^2+y^2+z^2-xy-yz-zx=?

Answer 1

Answer:

Step-by-step explanation:

x^2+y^2+z^2-xy-yz-zx =1/2{(x-y)^2+(y-z)^2+(z-x)^2}=1/2{(999-998)^2+(998-997)^2+(997-999)^2}=1/2(1+1+4)=1/2(6)=3