Final answer:
Q.E.D., which stands for 'Quod Erat Demonstrandum,' is a Latin phrase used by Greek mathematicians to indicate the completion of a proof. It translates to 'That which was to be demonstrated.' This term is rooted in the practices of ancient mathematicians like Pythagoras and Archimedes.
Step-by-step explanation:
At the end of a proof, Greek mathematicians often wrote Q.E.D., which stands for the Latin phrase Quod Erat Demonstrandum. This phrase translates to “That which was to be demonstrated.” It signifies that the proof has been completed and the result has been established. The practice dates back to ancient Greek mathematicians like Pythagoras and Archimedes, who were concerned with ideal proportions and made significant contributions to mathematics. Archimedes, for instance, calculated the value of pi to an impressive four-figure accuracy, a remarkable feat considering the decimal fraction system was not introduced to Europe until about a millennium later.
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