a +b2c 21. b+c+ 2a =2(a + b + c) ca2b

Verify (a + b + c) (a ^(2) +b ^(2) + c ^(2) - ab - b c - ca) = a ^(3) + b ^(2) + c ^(2) - 3 abc

If a^2+b^2+c^2=21 , and a + b + c = 7, then (ab + bc + ca) is equal to : यदि a^2+b^2+c^2=21 है तथा a +b + c = 7 है, तो (ab + bc + ca) का मान क्या होगा ?

Without expanding show that |b^2c^2 bc b+cc^2a^2 ca c+a a^2b^2a b a+b|=0 .

If a^(2) +b^(2) +c^(2) = ab + bc + ca then ((a+b)/(c ) + (b+c)/(a) + (c+a)/(b)) ((c )/(a+b) + (b)/(a+c) + (c )/(a+b)) =?