Advertisement

Let's fly back again to the days of dinosaurs and no calculators!

If math geeks had to calculate a decimal for something like

3 / sqrt(2)

things got really ugly. 

They'd have to use a table to get the value for sqrt(2)...  Then, they'd have to do the long division by hand:

sqrt(2) is approximately equal to 1.414 ...  3.000 divided by 1.414 (long division)

Yuck!

So, it was a LOT easier for them if there wasn't a radical in the denominator.

They created a fun little game called "rationalizing the denominator."

Here's how it goes:

3 / sqrt(2) = ( 3 / sqrt(2) )( sqrt(2) / sqrt(2) ) = ( 3*sqrt(2) ) / ( sqrt(2)*sqrt(2) ) = ( 3*sqrt(2) / sqrt(4) ) = ( 3*sqrt(2) ) / 2
Multiply by a magic 1.