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based on an earlier version of the Wolfram Language.
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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.
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