Quad Erat Demonstrandum
Were studying Trigonometric Identities and Sum and Differences Identities so I decided to make a post about Q.E.D and here's what I found:
- Quod Erat Demonstrandum(KWAWD eh-RAHT dem-on-STRAHND-um) “That which was to have been proved.” Traditionally placed at the end of proofs, the QED is now usually indicated by a small square. A few students have clung to use of the traditional letters, in the hope they might be interpreted as “quite elegantly done
- A great many Latin phrases are still in common everyday use in English such as quid pro quo ("something for something"), sine qua non ("without which not") and status quo ("state in which").
- Besides from Q.E.D., Latin terms are commonly used in mathematics. Quod Erat Faciendum(KWAWD eh-RAHT FAH-kee-END-um) “That which was to have been shown.” Abbreviated QEF, it was traditionally used to mark the end of a solution or calculation. It is rarely used now. Lets impress our professor by putting it at the end of exam problems.