prove that a^2+b^2+c^2-ab-bc-ca is non negative

 Solution:-

if a2+b2+c2-ab-bc-ca=0 then prove that a=b=c
prove that a² b² c² ab-bc-ca is always non negative for all values of a, b and c
a2+b2+c2=ab+bc+ca a=b=c
a2+b2+c2-ab-bc-ca is equal to
prove a2 + b2 + c2 ab-bc-ca
a^2+b^2+c^2-ab-bc-ca identity
a 2 b 2 c 3 ab bc ca
if a^2+b^2+c^2+ab+bc+ca <=0