# Not sure how to rationalize the denominator

• April 9th 2011, 06:11 AM
mathguy80
Not sure how to rationalize the denominator
Hi All,

Simplify the following expression

$
\dfrac
{
(b+c)^{\frac{-3}{8}} -
(b-c)^{\frac{-3}{8}}
}
{(b^2 - c^2)^{\frac{5}{8}}
}
$

I am unclear on how to proceed with this problem. Your help is much appreciated. Thanks.
• April 9th 2011, 06:21 AM
Prove It
Try multiplying top and bottom by $\displaystyle \left(b^2 - c^2\right)^{\frac{3}{8}}$.
• April 9th 2011, 08:03 AM
mathguy80
Ah cool! I see. So Rationalizing here is to try to get the power of the denominator = 1. That works out, Thanks!