Question

Find the value of a2+ b2+ c2 when a+b+c=√17 and ab + bc+ ca=2

Answer 1

Answer:

                   13

Step-by-step explanation:

We do this problem by using the formula:

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

Given :

             a + b + c = √17 --------------> Equation 1    AND

            ab + bc + ca = 2 --------------> Equation 2

        We put Equation 1 and Equation 2 in that formula, then we get

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

       But before substituting we take 2 common from 2ab + 2bc + 2ca

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

         Now lets substitute

          (√17)² = a² + b² + c² + 2(2)

          17 = a² + b² + c² + 4      (Square and square root get cancelled)

          17 - 4 = a² + b² + c²

          a² + b² + c² = 13

                                                  HOPE U UNDERSTOOD

                                                          THANK YOU :)