Question

How can I rationalize (r^1/2 - r^-1/2)^2 ?

Answer 1

\[(\sqrt{r}-\frac{1}{\sqrt{r}})^2=r-2+\frac{1}{r}\]

Answer 2

\[\large \left (\sqrt{r}-\frac{1}{\sqrt{r}}\right )^2=\left ( \frac{r-1}{\sqrt{r}}\right )^2=\frac{r^2-2r+1}{r}=r-2+\frac{1}{r}\]

Answer 3

Use FOIL

Answer 4

Thank you :)

Answer 5

No problem. :D