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Word of the Day – Wednesday, January 4^{th} 




ERAT (ERawt) Quod
Erat Demonstrandum: ‘that which was to be
demonstrated’
Q.E.D. may be written at the end of mathematical proofs to show that the result required for the proof to be complete has been obtained. It is not seen as frequently now as it once was, since formal geometry is less commonly taught as a separate subject.
The term is also used both formally and informally in a wide variety of disciplines, as well as in everyday conversation in many parts of the Englishspeaking world.
Q.E.D. is a translation into Latin of the original Greek (hoper edei deixai) which was used by many early mathematicians including Euclid and Archimedes. Benedict De Spinoza also makes extensive use of the abbreviation Q.E.D. in his various works.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Q.E.D."

