This site is being phased out.
Sign function
From Mathematics Is A Science
Revision as of 14:46, 14 October 2012 by imported>WikiSysop
$$ f(x) = \begin{cases} -1 & \text{ if } x < 0 \\ 0 & \text{ if } x = 0 \\ 1 & \text{ if } x > 0 \end{cases} $$
Domain $f =(-\infty,\infty), f(0)= 0.$
