Question

x =6-√35 and 1/x = 6+√35
find x cube +1/x cube

Answer 1

Answer :

1,692

Step-by-step explanation :

x = 6 - √35            …(1)

1 / x = 6 + √35      …(2)

Now, adding (1) and (2)

x + 1 / x = 6 - √35 + 6 + √35

x + 1 / x = 6 + 6

x + 1 / x = 12

Cubing both the sides :

( x + 1 / x )³ = ( 12 )³

⇒ x³ + 1 / x³ + 3 ( x + 1 / x ) = 1,728

⇒ x³ + 1 / x³ + 3( 12 ) = 1,728

⇒ x³ + 1 / x³ + 36 = 1,728

⇒ x³ + 1 / x³ = 1,728 - 36

⇒ x³ + 1 / x³ = 1,692

Hence, the answer is 1,692

Answer 2

The answer is 1692 ...