Click here to reset the sandbox
--Lou.weird 10:17, 1 April 2007 (UTC)
r n − 2 / 1 − r 2 {\displaystyle r{\sqrt {n-2/1-r^{2}}}}
r n − 2 1 − r 2 {\displaystyle r{\sqrt {\frac {n-2}{1-r^{2}}}}}