Question

3+ √5/2
find value a²+1/a²​

Answer 1

Answer:

7

Step-by-step explanation:

1/a² = 1 / (3+√5)² /2²

      = (4/(3+√5)²) × ((3-√5)²/(3-√5)²)

      = (4×(3-√5)²) / 16

      = (3-√5)²/ 4

∴ a² + 1/a² = ((3+√5)² + (3-√5)²) / 4

                 = 2(9 + 5) /4

                 =  7