Search results
People also ask
Where did quod erat demonstrandum come from?
Why did Euclid use quod erat faciendum?
When was QED first used?
When was QED used in philosophy?
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.
Euclid used the Greek original of Quod Erat Faciendum (Q.E.F.) to close propositions that were not proofs of theorems, but constructions of geometric objects. For example, Euclid's first proposition showing how to construct an equilateral triangle , given one side, is concluded this way.
It was invented by Aristotle (384–322 B.C.) in Athens, and recorded in a group of writings known as the Organon. In one of these works, the Prior Analytics, Aristotle attempted to provide a complete analysis of the valid forms of reasoning.
According to Veronika Oberparleiter, the earliest known use in print of the phrase quod erat demonstrandum in a Euclid translation appears in the translation by Bartholemew Zamberti published in Venice in 1505.
The earliest known use of the phrase quod erat demonstrandum is in the early 1600s. OED's earliest evidence for quod erat demonstrandum is from 1614, in the writing of William Bedwell, Arabist and mathematician.
Jan 21, 2009 · Demonstrative logic, the study of demonstration as opposed to persuasion, is the subject of Aristotle's two-volume Analytics. Many examples are geometrical. Demonstration produces knowledge (of the truth of propositions). Persuasion merely produces opinion.
Sep 28, 2017 · Origin of Q.E.D.: 1760, abbreviation of Latin quod erat demonstrandum "which was to be demonstrated." ... See more.
