Posted by TUHITUHI on .
prove that a^2+b^2+c^2abbcca is always non negative for all the value of a' b and c

math 
Steve,
(ab)^2 + (ac)^2 + (bc)^2 >= 0
a^2  2ab + b^2 + a^2  2ac + c^2 + b^2  2bc + c^2 >= 0
2a^2 + 2b^2 + 2c^2  2(ab+ac+bc) >= 0
divide by 2.