Question

I need 6th question in the paper

Answer 1

The correct and best answer is 8 using that formula

Answer 2

8

Explanation:

`a = 1 - √(2)`

`(a - (1)/(a))^3 =`

`= ((a^2)/(a) - (1)/(a))^3`

`= ((a^2 - 1)/(a))^3`

`= (((a + 1)(a - 1))/(a))^3`

`= (((1 - √(2) + 1)(1 - √(2) - 1))/(a))^3`

`= (((2 - √(2))(-√(2)))/(1 - √(2)))^3`

`= (((-2√(2) + √(2)√(2))/(1 - √(2)))^3`

`= ((2 - 2√(2))/(1 - √(2)))^3`

`= ((2(1 - √(2)))/(1 - √(2)))^3`

`= 2^3`

`= 8`