Question

prove that x^2+y^2+z^2-xy-yz-zx is always positive ...

Answer 1

because the function haVe even power then the value of that function is always positive so x^2 +y ^2 + z^2 is always positive if the value of x, y ,z = 0 then the value of function will be 0 if x,y ,z is not equal to 0 then this function will be also positive value.

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