Question

$if a=3+root5/2, then find the value of a^2+1/a^2$

Answer 1

a = (3 + √5)/2

1/a = 2/(3+√5)
1/a = (3-√5)/2

now,
a² + 1/a² = (a + 1/a)² -2

={(3+√5)/2 +(3-√5)/2}² -2

=(3)² - 2

=7 ( answer)

Answer 2

Answer:

Answer is 7

Step-by-step explanation: