Question

(i) If a² + b² + c² = 12 and a+b+c = 23 ,Find : ab+bc+ca.​

Answer 1

Answer:

ANSWER

Formula,

(a+b+c)2=a2+b2+c2+2ab+2bc+2ca

=a2+b2+c2+2(ab+bc+ca)

Given,

⇒92=a2+b2+c2+2(23)

⇒81−46=a2+b2+c2

∴a2+b2+c2=35