Numerator

Numerator[expr]

gives the numerator of expr.

Details and Options

  • Numerator picks out terms which do not have superficially negative exponents. Denominator picks out the remaining terms.
  • An exponent is "superficially negative" if it has a negative number as a factor.
  • The standard representation of rational expressions as products of powers means that you cannot simply use Part to extract numerators.
  • Numerator can be used on rational numbers.

Examples

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Basic Examples  (1)

Extract the numerator of a rational number:

In[1]:=
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Out[1]=

Extract the numerator of a rational expression:

In[2]:=
Click for copyable input
Out[2]=

Scope  (6)

Options  (2)

Properties & Relations  (4)

See Also

Denominator  ExpandNumerator  Rational

Tutorials

Introduced in 1988
(1.0)