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.
Examplesopen allclose all
Basic Examples (1)
Extract the numerator of a rational number:
Extract the numerator of a rational expression:
Select terms without syntactically negative exponents:
All exponents syntactically negative:
No syntactically negative exponents:
Numerator automatically threads over lists:
Find numerators over integers modulo :
Numerators of trigonometric functions:
Properties & Relations (4)
Denominator gives the terms with negative exponents:
An expression is a quotient of its numerator and denominator:
Use Cancel to cancel common factors between the numerator and the denominator:
Together writes an expression as a fraction and cancels common terms: