A 2 b 2 c 2 ab bc ac 0 July 8, 2019 16 32 64 128 If a 2 b 2 c 2 ab bc ac 0 then C 2 ab x 2 2 a 2 bc x b 2 ac 0 If a b c 0 prove that a 2 bc b 2 ac c 2 ab 3