3 divided by square root of 2 minus 1

3/√2−1

So you basically would just do order of operations.

first find the square root of 2.

3/1.41-1

then divide 3 by 1.41

2.13-1

subtract

your answer is 1.13

I assume you mean: Rationalize the denominator of

$$\\\frac{3}{\sqrt2-1}\\\\ =\frac{3}{\sqrt2-1}\times \frac{\sqrt2+1}{\sqrt2+1}\\\\ =\frac{3(\sqrt2+1)}{(\sqrt2-1)(\sqrt2+1)}\\\\ =\frac{3\sqrt2+3}{(2-1)}\\\\ =3\sqrt2+3$$