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We all use mathematical symbols in our daily life. But do we know who discovered them? For example + (plus) ? In this presentation we are going to learn who discovered mathematical symbols and why. Are you ready? OK. Let's start!

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William Oughtred (1574-1660) who discovered "multiplying symbol" in Mathematics. He is the first man used "x" in maths. A few years later, a man named "Leibniz" (1646-1715) used "." (dot) in Mathematics. In that time Leibniz was the most popular man. He said that the letter "x" and the multiply symbol "x" can be mixed easily that's why we are using dot (.) in Mathematics.

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The union sign means “take the elements that are in either set”, and ∩ (the intersection sign) means “take the elements that the two sets have in common”. They were introduced in the 1888 book Calcolo geometrico secondo l’Ausdehnungslehre di H. Grassmann preceduto

dalle operazioni della logica deduttiva (“Geometric Calculus based upon the teachings of H. Grassman, preceded by the operations of deductive logic”) by Giuseppe Peano (1858-1932).

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Everyone knows that, in addition we

all use plus. (+) Jean Viedman in 1489 he discovered plus in mathematics. First he used this symbol in his own book. Called "Practical Arithmetic." But in some sources all so you can see this man's name: "Robert Recorde." In some sources they say that first Robert Recorde used the plus in his own book. Also today we don't know that really, WHICH one is true, which one is false. Who do YOU think?

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William Oughtred was born at Eton in Buckinghamshire (now part of Berkshire), and educated there and at King's College, Cambridge, of which he became fellow. Being admitted to holy orders, he left the University of Cambridge about 1603, for a living at Shalford; he was presented in 1610 to the rectory of Albury, near Guildford in Surrey, where he settled. And he died in 1660.

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John Wallis (1616-1703) was the first mathematician to use the symbol to denote an infinite quantity.

The symbol of infinity was used by the romans to express a "large" number, and in many cases this large number was 1,000, which was "large" indeed at the time.

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John Wallis (23 November 1616 – 28 October 1703) was an English mathematician who is given partial credit for the development of infinitesimal calculus. He is also credited with introducing the symbol for infinity. He similarly used for an infinitesimal. Asteroid 31982 Johnwallis was named after him.

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Giuseppe Peano (27 August 1858 – 20 April 1932) was an Italian mathematician. The author of over 200 books and papers, he was a founder of mathematical logic and set theory, to which he contributed much notation. By 1901, Peano was at the peak of his mathematical career.

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1925 Peano switched Chairs unofficially from Infinitesimal Calculus to Complementary Mathematics, a field which better suited his current style of mathematics. This move became official in 1931. Giuseppe Peano continued teaching at Turin University until the day before he died, when he suffered a fatal heart attack.

The less than sign mean “is strictly less than”, and > (the greater than sign) means “is strictly greater than”. They ﬁrst appeared in Artis Analyticae Praxis ad Aequationes Algebraicas Resolvendas (“The Analytical Arts Applied to Solving Algebraic Equations”) by Thomas Harriot (1560-1621), which was published posthumously in 1631.

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Thomas Harriot was an English astronomer, mathematician, ethnographer, and translator. He is sometimes credited with the introduction of the potato to the British Isles. Harriot was the first person to make a drawing of the Moon through a telescope, on July 26, 1609, over four months before Galileo. He died on 2 July 1621,

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The null set or empty set symbol means “the set without any elements in it” and was ﬁrst used in the 1939 book El´ements de math´ematique ´ by N. Bourbaki (a group of primarily European mathematicians—not a single person). It was borrowed simultaneously from the Norwegian, Danish and Faroese alphabets by group member Andr´e Weil (1906-1998).

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There is two division symbols. Let's look the first one!

First one is obelus. The obelus (÷) was first used as a division symbol by Johann Rahn (or Rhonius) (1622-1676) in 1659 in Teutsche Algebra (Cajori vol. 2, page 211).

Second one is the colon (:). The colon (:) was used in 1633 in a text entitled Johnson Arithmetik; In two Bookes (2nd ed.: London, 1633). However Johnson only used the symbol to indicate fractions (for example three-fourths was written 3:4); he did not use the symbol for division "dissociated from the idea of a fraction" (Cajori vol. 1, page 276). But today in division we use both symbols.

Johann Rahn (1622–1676) was a (* March 10, 1622 Töss (Winterthur), † May 25, 1676 in Zurich) Swiss mathematician who is credited with the first use of the division symbol, ÷ (obelus) and the therefore sign, He is known for his Teutsche algebra, the first time the Geteiltzeichen characters appear in print.

Bourbaki was a pseudonym adopted in 1934 by a group of young French mathematicians for their joint activities.he branches upon which Bourbaki exerted the deepest influence were algebra, topology, and functional analysis. Notations such the symbol (for the empty set, and terms such as injective, surjective, and bijective owe their widespread use to their adoption in the Eléments de mathématique. Bourbaki’s Eléments came to comprise a large collection of more than seven thousand pages. The first chapter appeared in 1935, and new ones continued to appear until the early 1980s.

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In mathematical proof, the therefore sign is sometimes placed before a logical consequence, such as the conclusion of a syllogism. The symbol consists of three dots placed in an upright triangle and is read therefore. According to Cajori, A History of Mathematical Notations, Johann Rahn used both the therefore and because signs to mean "therefore"; in the German edition of Teutsche Algebra (1659) the therefore sign was prevalent with the modern meaning, but in the 1668 English edition Rahn used the because sign more often to mean "therefore". Other authors in the eighteenth century also used three dots in a triangle shape to signify "therefore", But as with Rahn, there wasn't much in the way of consistency as to how the triangle was oriented; because with its current meaning appears to have originated in the nineteenth century.

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The word "radix" was used for square root in the thirteenth century or

so, and was abbreviated as "R" or R with a slash though the right leg

of the R, like the Rx symbol at pharmacies. The symbol that looks like a check (radical sign without the "roof") originated in Germany, in the 1500's. It started out looking quite like a musical note. If you had a long expression under the radical

sign, the expression was put in parentheses, and later, placed with a

line over it. This is where the current symbol came from. Descartes

in his _La Geometrie_ (1637) seems to be the first to place the line

on top for grouping. So, no one really "invented" the sign - it developed over the years.

But if you need a specific person, Descartes seems to be the one to first use the present day version of the symbol.

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The summation symbol (the Greek letter sigma) was first used by Leonhard Euler (1707-1783) The concept of sigma notation means to sum up all terms and uses three parts to form math statements, like ∑i ai. The Greek letter ∑ is the summation operator and means the sum of all, i is called the index number, and ai refers to a series of terms to be added together. This mathematical notation is used to compactly write down the equations in which summing all terms is required. It can be used, for example, to show the addition of all employees’ hours at a company. If ai is the hours worked by a certain employee and there are n employees, then ∑i ai means to add a1+a2+a3+a4…an .