Question

if x=1-√2,find the value of (x-1/x)cube

Answer 1

x = 1 - √2

1/x  =      1       =      (1 + √2)      =   - (1 + √2)

           1 - √2          (1)² - (√2)²

x - 1/x = 1 - √2 - [ ⁻ (1 + √2) ]

x - 1/x  = 1 - √2 + 1 + √2  = 2

(x - 1/x)³ = 2³ = 8