question_answer 1)

Show that  = 1+ a2 + b2 + c2.  

Answer:

      Multiply C1, C2 and C3 by a, b and c respectively, we get             Taking a, b and c as common from  we get             Operate  we get                     Operate  we get                        Expand along C1             = (1 + a2 + b2 + c2) (1 ? 0)       = 1 + a2 + b2 + c2