Question

If x=2015, y=2014, z=2013 when x^2+y^2+z^2-xy-yz-zx=?=?

Answer 1

Answer:

this is your solution.

Answer 2

IDENTITY:-

x²+y²+z²-xy-yz-zx=(1/2)×[(x-y)²+(y-z)²+(z-x)²]

SOLUTION:-

x=2015

y=2014

z=2013

Putting Values in the identity,

x²+y²+z²-xy-yz-zx = (1/2)×[(2015-2014)²+(2014-2013)²+(2013-2015)²]

= (1/2)×[1²+1²+(-2)²]

= (1/2)×[1+1+4]

= (1/2)×[6]

= 3

ANSWER:- 3