Q.E.D.

abbreviation to indicate the completion of a mathematical proof

Q.E.D. is an acronym or initialism of the Latin phrase quod erat demonstrandum, which means "what was to be demonstrated". In other words, Q.E.D. means "something was to be proven, and now it has been done".[1][2]

History

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In the European Renaissance, scholars often wrote in Latin. The phrases Q.E.D. was often used at the end of mathematical or philosophical proofs.[3]

Equivalents in other languages

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Q.E.D. is used in many languages, including:

Language Abbreviations Stands for...
Arabic و.هـ.م وهو المطلوب إثباته
Bengali অ. সি. অতঃ সিদ্ধ
Chinese 证毕。 证明完毕
Croatian Š.T.D. što je trebalo dokazati
Czech C.B.D. což bylo dokázati
Dutch w.t.b.w. wat te bewijzen was
English w.w.t.b.p. which was to be proven
Esperanto K.E.P kio estis pruvenda
Estonian M.O.T.T. mida oligi tarvis tõestada
Finnish M.O.T. mikä on todistettu
French C.Q.F.D. ce qu'il fallait démontrer
German w.z.b.w. was zu beweisen war
Greek Ο.Ε.Δ. όπερ έδει δείξαι
Italian C.V.D. come volevasi dimostrare
Hebrew .מ.ש.ל מה שצריך להוכיח
Hindi इ.सि. इति सिद्धम्
Polish c.b.d.u. co było do udowodnienia
Portuguese C.Q.D. como queríamos demonstrar
Russian ч.т.д. что и требовалось доказать
Serbian ш.т.д. што је и требало доказати
Slovenian q.e.d (quonc)/konc enga dokaza
Tamil நி.வே. நிரூபிக்கப்படவேண்டியது
Thai ซ.ต.พ. ซึ่งต้องพิสูจน์
Hungarian E.K.B. Ezt kellett bizonyítani
Spanish Q.E.D. queda entonces demostrado
queda esto demostrado
Swedish V.S.B.
V.S.V
vilket skulle bevisas
vilket skulle visas
Vietnamese đpcm. Điều phải chứng minh
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References

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  1. "The Definitive Glossary of Higher Mathematical Jargon: Q.E.D." Math Vault. 2019-08-01. Retrieved 2020-09-06.
  2. Ben-Menahem, Ari. (2009). Historical Encyclopedia of Natural and Mathematical Sciences, Vol. 1, p. 5603; Fergusson, Rosalind. (2009). Shorter Dictionary of Catch Phrases, p. 109.
  3. Weisstein, Eric W. "Q.E.D." mathworld.wolfram.com. Retrieved 2020-09-06.

Other websites

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