Euclid's method for finding the greatest common divisor (GCD) of two starting lengths BA and DC, both defined to be multiples of a common "unit" length. The length DC being shorter, it is used to "measure" BA, but only once because remainder EA is less than DC. EA now measures (twice) the shorter length DC, with remainder FC shorter than EA. Then FC measures (three times) length EA. Because there is no remainder, the process ends with FC being the GCD. On the right Nicomachus's example with numbers 49 and 21 resulting in their GCD of 7 (derived from Heath 1908:300).
In mathematics, the Euclidean algorithm, or Euclid's algorithm, is an efficient method for computing the greatest common divisor (GCD) of two integers (numbers), the largest number that divides them both without a remainder. It is named after the ancient Greek mathematicianEuclid, who first described it in his Elements (c. 300 BC).
It is an example of an algorithm, a step-by-step procedure for performing a calculation according to well-defined rules,
and is one of the oldest algorithms in common use. It can be used to reduce fractions to their simplest form, and is a part of many other number-theoretic and cryptographic calculations.
The Euclidean algorithm is based on the principle that the greatest common divisor of two numbers does not change if the larger number is replaced by its difference with the smaller number. For example, 21 is the GCD of 252 and 105 (as 252 = 21 × 12 and 105 = 21 × 5), and the same number 21 is also the GCD of 105 and 252 − 105 = 147. Since this replacement reduces the larger of the two numbers, repeating this process gives successively smaller pairs of numbers until the two numbers become equal. When that occurs, they are the GCD of the original two numbers. By reversing the steps or using the extended Euclidean algorithm, the GCD can be expressed as a linear combination of the two original numbers, that is the sum of the two numbers, each multiplied by an integer (for example, 21 = 5 × 105 + (−2) × 252). The fact that the GCD can always be expressed in this way is known as Bézout's identity. (Full article...)
...that the country's highest mountain, Mount Olympus was said to be the home of the Greek Gods in ancient Greek religion?
...that the Olympic Games, originated in Greece 3000 years ago, and that the 1st games of the modern Olympics were held in Greece in 1896, as a revival of the Games?
...that the Greek state comprises only the centre of the ancient Greek world, which comprised also Southern Italy, the coastal areas of modern Turkey and the Black Sea, as well as some colonies in North Africa, Southern France and Spain?
...that even though the modern Greek state was established in 1832, some areas of Greece were not liberated until after the Balkan Wars?
Sing, O goddess, the anger of Achilles son of Peleus, that brought countless ills upon the Achaeans. Many a brave soul did it send hurrying down to Hades, and many a hero did it yield a prey to dogs and vultures, for so were the counsels of Zeus fulfilled from the day on which the son of Atreus, king of men, and great Achilles, first fell out with one another.
Greek art began in the Cycladic and Minoan prehistorical civilization. The art of ancient Greece has exercised an enormous influence on the culture of many countries from ancient times until the present, particularly in the areas of sculpture and architecture. In the West, the art of the Roman Empire was largely derived from Greek models. In the East, Alexander the Great's conquests initiated several centuries of exchange between Greek, Central Asian and Indian cultures. During the Renaissance , the humanist aesthetic and the high technical standards of Greek art inspired generations of European artists.Read more...
A short video of the main sites at the ancient sanctuary of Delphi in Central Greece. Delphi was considered to be the center of the world by the Greeks and the most important oracle in the Greek world.