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Im

  • Im[ z ] gives the imaginary part of the complex number z.
  • Im[ expr ] is left unevaluated if expr is not a numeric quantity.
  • See the Mathematica book: Section 1.1.5Section 3.2.2.
  • See also: Re, Abs, Arg, ComplexExpand.

    Further Examples

    Here are the imaginary parts of two complex numbers.

    In[1]:=

    Out[1]=

    Since a or b might be complex, Im doesn't evaluate to b. ComplexExpand assumes the variables are real.

    In[2]:=

    Out[2]=