\(\sqrt{2}\) - 1
1 - \(\sqrt{2}\)
\(\frac{\sqrt{2} - 1}{2}\)
\(\frac{1 - \sqrt{2}}{2}\)
Correct answer is A
\(\frac{1}{\sqrt{2} + 1}\) x \(\frac{\sqrt{2} - 1}{\sqrt{2} - 1}\)
= \(\frac{\sqrt{2} - 1}{2 - 1}\)
= \(\frac{\sqrt{2} - 1}{1} = \sqrt{2} - 1\)