Question

if a=(3+✓5)/2, then find the value of a^2+1/a^2

Answer 1

first find the values of a^2 and 1/a^2 using a and then add them


a^2 = (14+6√5)/4

1/a^2 = ((2(3-√5))/4)^2 =(14 -6√5)/4

now a^2 + 1/a^2 = 7