Q.E.D. facts for kids
Q.E.D. is a short way to write a Latin phrase: quod erat demonstrandum. This phrase means "what was to be shown." It's like saying, "We set out to prove something, and now it's done!" People use Q.E.D. to show that they have finished proving a statement or solving a problem.
History of Q.E.D.
During the European Renaissance (a time of great learning and art), scholars often wrote their important works in Latin. They used Q.E.D. at the end of mathematical proofs or philosophical arguments. It was a common way to signal that they had successfully shown what they intended to prove.
How Other Languages Say It
The idea of saying "it has been proven" is important in many languages. Here's how some other languages express a similar idea to Q.E.D.:
| Language | Abbreviations | Stands for... |
|---|---|---|
| Arabic | و.هـ.م | وهو المطلوب إثباته |
| Bengali | অ. সি. | অতঃ সিদ্ধ |
| Croatian | Š.T.D. | što je trebalo dokazati |
| Czech | C.B.D. | což bylo dokázati |
| 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 |
Images for kids
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Spinoza's original text of Ethics, Part 1. Q.E.D. is used at the end of DEMONSTRATIO of PROPOSITIO III.
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Philippe van Lansberge's 1604 Triangulorum Geometriæ used quod erat demonstrandum to conclude some proofs; others ended with phrases such as sigillatim deinceps demonstrabitur, magnitudo demonstranda est, and other variants.
See also
In Spanish: Quod erat demonstrandum para niños
