function

can you write another way to make this equation:

$f(x)= \begin{Bmatrix} 1, & x>0\\ -1, & x<0\\ \end{Bmatrix}$

you can't rewrite it as this or it will be cheating:

$f(x)= \begin{Bmatrix} -1, & x<0\\ 1, & x>0\\ \end{Bmatrix}$