Question

If x = 1 - √2, then find the value of (x – 1/x )3

Answer 1

Answer:

x=1-√2

1/x=1/(1-√2)

=(1+√2)/(1-√2)(1+√2)

=(1+√2)/{(1)^2-(√2)^2

=(1+√2)/(1-2)

= -(1+√2)

(x-1/x)^3

={(1-√2)+(1+√2)}^3

=(1-√2+1+√2)^3

=(2)^3

=8