Question

Example 10. If x = 1+ √2, then find the value
of (x-1/x)^3
-

Answer 1

Answer:

20- 14√2

Step-by-step explanation:

$( { \frac{x - 1}{x} )}^{3} = { (\frac{ \sqrt{2} }{1 + \sqrt{2} } })^{3} \\ = \frac{2 \sqrt{2} }{5 \sqrt{2} + 7 } \\ = 20 - 14 \sqrt{2}$