• Sign[x] gives -1, 0 or 1 depending on whether x is negative, zero, or positive.
• Mathematical function (see Section A.3.10
• 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
• New in Version 1; modified in 3.