Question

If x+y+z=0, then show that x²+y²+z²=-2(xy+yz+zx).

Answer 1

by using formula

(x+y+z)² = x²+y²+z² + 2xy+2yz+2zx

put x+y+z = 0

then we get,

x²+y²+z²+2(xy+yz+zx) =0

x² + y² + z² = - 2(xy+yz+zx)

Answer 2

Answer:

Is this kashyap asking the doubt