quaternion

== English == === Etymology === From Middle English quaterniǒun, from Late Latin quaterniō, from quaternī (“four each”) + -iō, from quater (“four times”). Doublet of kern. The mathematics sense was coined by Irish mathematician and astronomer William Rowan Hamilton in 1843. === Pronunciation === (UK) IPA(key): /kwəˈtɜːni.ən/ (US) IPA(key): /kwɑˈtɜɹniɑn/, /kwə-/, /-ən/ === Noun === quaternion (plural quaternions) A group or set of four people or things. A word of four syllables. (mathematics) A type of four-dimensional hypercomplex number consisting of a real part and three imaginary parts (real multiples of distinct, independent square roots of −1 denoted by i, j and k); commonly used in vector mathematics and as an alternative to matrix algebra in calculating the rotation of three-dimensional objects. ==== Synonyms ==== (group of four): foursome, tetrad; see also Thesaurus:quartet ==== Hypernyms ==== (mathematics): hypercomplex number ==== Hyponyms ==== (mathematics): versor ==== Derived terms ==== ==== Translations ==== === See also === (mathematics): octonion sedenion trigintaduonion pathion chingon routon voudon === References === === Further reading === Cayley–Dickson construction on Wikipedia.Wikipedia == French == === Pronunciation === === Noun === quaternion m (plural quaternions) (mathematics) quaternion === Further reading === “quaternion”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012