September 10, 2009
No CommentsHow to Rationalize the Denominator
Description
This video is a quick tutorial of how to rationalize the denominator in both normal expressions and binomial expressions. Many example problems are provided in this video.
Overview
Rationalizing the denominator refers to something you must do in math when you are given a fraction with a square root of a number like 2 or 3, that comes out to be a very long decimal. Instead of giving up and saying you can’t solve the problem, you can use a math trick to help you. This math trick is multiplying by one. Nothing happens to a number when you multiply it by one. 1 * n = n, and so on. But, here\’s the trick: write one as something different. The fractions 2/2 or sqrt(6)/sqrt(6) are also equal to one. You need to look at your denominator. If the number in your denominator is sqrt(5), then the number you will multiply the fraction by is sqrt(5)/sqrt(5). Follow your rules for fraction multiplication, and you will see that there is now no radical in the denominator! It is okay to have a radical in the numerator after doing this.
