Question

if n=3+√5/2 ,show that n+1/n=3,also find n^3+1/n^3

Answer 1

Solution :

Given n + 1/n = 3 ---( 1 )

n³ + 1/n³

= ( n + 1/n )³ - 3(n + 1/n )

= 3³ - 3 × 3

= 27 - 9

= 18

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