x^2 / (Square Root(x+1)) - (Square Root(x-1))
How to I multiply the conjugate on the bottom? I really just don't know how to do it
$\displaystyle
\frac{x^2}{\sqrt{x+1}-\sqrt{x-1}}$
Multiply the top and bottom by $\displaystyle \frac{\sqrt{x+1}+\sqrt{x-1}}{\sqrt{x+1}+\sqrt{x-1}}$
and hence it equals $\displaystyle \frac{x^2}{2}(\sqrt{x+1}+\sqrt{x-1})$
Use $\displaystyle (a+b)(a-b)=a^2-b^2$