Rationalization (mathematics)

The rationalization of denominators is to get rid of radicals that are in the denominator (the bottom part of a fraction). It works by dividing the bottom radical by itself, then multiplying that by the first expression.

[math]\displaystyle{ \frac{a}{\sqrt{b}} = \frac{a}{\sqrt{b}} \times \frac{\sqrt{b}}{\sqrt{b}} = \frac{a\sqrt{b}}{\sqrt{b}^2} = \frac{a\sqrt{b}}{b} }[/math]