Phrase guide

dual number

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

A grammatical number denoting a quantity of exactly two.

Definition source: English Wiktionary via Wiktextract

Topics: grammar, human-sciences, linguistics, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

An element of an algebra (the algebra of dual numbers) which includes the real numbers and an element ε which satisfies ε ≠ 0 and ε2 = 0.

Definition source: English Wiktionary via Wiktextract

Topics: algebra, mathematics, sciences

Examples

  • If f(x) is a polynomial or a power series then its derivative can be obtained “automatically” using dual numbers as follows: f'(x)#61;#123;f(x#43;#92;epsilon)-f(x)#92;over#92;epsilon#125; where f(x#43;#92;epsilon) should be expanded using the algebra of dual numbers. The role of the ε is therein similar to that of an infinitesimal.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: hypercomplex number

History

Etymology

No etymology was provided for this word.

Across languages

Translations

1 source translations are retained for this English entry.

  • Polish: liczba dualna — element of the algebra of dual numbers