Question

if a+b+c =0 a squre +b squre +c square =16 find the value of ab +bc+ca

Answer 1

we know that (a+b+c)2=a2+b2+c2+2ab+2bc+2ac
=putting given values
=0=16+2(ab+bc+ca)
value of ab+bc+ca=-8
Hope it will help you

Answer 2

The answer will be -8. (a+b+c)^2= a^2+b^2+ c^2 + 2(ab+bc+ca)
therefore, 0^2= 16 + 2(ab+bc+ca)
ab+bc+ca=-16/2= -8