12+1\;\frac{1}{\sqrt{2} + 1}2+11 x 2 − 12−1\;\frac{\sqrt{2}\;-\;1}{\sqrt{2} - 1}2−12−1
= 2 − 12 − 1\;\frac{\sqrt{2}\;-\;1}{2\;-\;1}2−12−1
= 2 − 11=2−1\;\frac{\sqrt{2}\;-\;1}{1} = \sqrt{2} - 112−1=2−1
