If Root(2) = 1.4142, then [Root(2) − 1 / Root(2) + 1] is equal to

Hi,
expression is

$$\frac{\sqrt{2}-1}{\sqrt{2}+1}$$
multiply denominator and numerator with $$\sqrt{2}+1$$, since (a+b)(a-b)=$$a^{2}-b^{2}$$
you will get,
$$\frac{1}{(\sqrt{2}+1)^{2}}$$
which is $$\frac{1}{2\sqrt{2}+3}$$
Again Multiply numerator and denominator with $$3-2\sqrt{2}$$ and apply (a+b)(a-b)=$$a^{2}-b^{2}$$
you will get the answer as $$3-2\sqrt{2}$$