Question

can you please prove the question given in the pic.​

Answer 1

Step-by-step explanation:

we know if a real number a is positive if a>0

so,

x²+y²+z²-xy-yz-zx

=>1/2{2x²+2y²+2z²-2xy-2yz-2zx}

=>1/2{(x-y)²+(y-z)²+(z-z)²}>0

which is always greater than zero as if A is real number then A² will always be positive