Q.E.D.

Q.E.D. is an acronym or initialism of the Latin phrase , 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".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.

History
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.

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

 Language Abbreviations Stands for... Arabic و.هـ.م  Bengali অ. সি.  Chinese 证毕。  Croatian Š.T.D.  Czech C.B.D. Dutchw.t.b.w.wat te bewijzen wasEnglishw.w.t.b.p.which was to be provenEsperantoK.E.Pkio estis pruvenda Estonian M.O.T.T.  Finnish M.O.T.  French C.Q.F.D.  German w.z.b.w.  Greek Ο.Ε.Δ.  Italian C.V.D.  Hebrew .מ.ש.ל  Hindi इ.सि.  Polish c.b.d.u.  Portuguese C.Q.D.  Russian ч.т.д.  Serbian ш.т.д.  Slovenian q.e.d  Tamil நி.வே.  Thai ซ.ต.พ.  Hungarian E.K.B.  Spanish Q.E.D.   Swedish V.S.B.V.S.V  Vietnamese đpcm. 

 Related pages 

 Mathematical proof

References

Other websites
Earliest Known Uses of Some of the Words of Mathematics (Q)

Category:Latin words and phrases