This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)


gives -1, 0 or 1 depending on whether x is negative, zero, or positive.
  • Mathematical function, suitable for both symbolic and numerical manipulation.
  • For non-zero complex numbers z, Sign[z] is defined as z/Abs[z].
  • Sign tries various transformations in trying to determine the sign of symbolic expressions.
  • For exact numeric quantities, Sign internally uses numerical approximations to establish its result. This process can be affected by the setting of the global variable $MaxExtraPrecision.
  • Sign automatically threads over lists.
New in 1 | Last modified in 3