What does Q.E.D. mean?
Answer
Q.E.D. (also written QED and QED) is an initialism of the Latin phrase quod erat demonstrandum meaning “what was to be demonstrated” or “what was to be shown.” Traditionally, the phrase is placed in its abbreviated form at the end of a mathematical proof or philosophical argument when the original proposition has been restated exactly, as the conclusion of the demonstration or completion of the proof.