What does the symbol q mean in the formula. Mathematical signs

Balagin Victor

With the discovery of mathematical rules and theorems, scientists came up with new mathematical notations and signs. Mathematical signs are symbols, intended for recording mathematical concepts, sentences and calculations. In mathematics, special symbols are used to shorten the notation and more accurately express the statement. In addition to numbers and letters of various alphabets (Latin, Greek, Hebrew), the mathematical language uses many special symbols invented over the past few centuries.

Download:

Preview:

MATHEMATICAL SYMBOLS.

I've done the work

7th grade student

GBOU secondary school No. 574

Balagin Victor

2012-2013 academic year

MATHEMATICAL SYMBOLS.

1. Introduction

The word mathematics came to us from ancient Greek, where μάθημα meant “to learn”, “to acquire knowledge”. And the one who says: “I don’t need mathematics, I’m not going to become a mathematician” is wrong.” Everyone needs mathematics. Revealing amazing world numbers surrounding us, it teaches us to think more clearly and consistently, develops thought, attention, fosters perseverance and will. M.V. Lomonosov said: “Mathematics puts the mind in order.” In a word, mathematics teaches us to learn to acquire knowledge.

Mathematics is the first science that man could master. The oldest activity was counting. Some primitive tribes counted the number of objects using their fingers and toes. Rock painting, preserved to this day from the Stone Age, depicts the number 35 in the form of 35 sticks drawn in a row. We can say that 1 stick is the first mathematical symbol.

The mathematical “writing” that we now use - from designating unknowns with the letters x, y, z to the integral sign - developed gradually. The development of symbolism simplified work with mathematical operations and contributed to the development of mathematics itself.

From ancient Greek “symbol” (Greek. symbolon - sign, omen, password, emblem) - a sign that is associated with the objectivity it denotes in such a way that the meaning of the sign and its object are represented only by the sign itself and are revealed only through its interpretation.

With the discovery of mathematical rules and theorems, scientists came up with new mathematical notations and signs. Mathematical signs are symbols designed to record mathematical concepts, sentences and calculations. In mathematics, special symbols are used to shorten the notation and more accurately express the statement. In addition to numbers and letters of various alphabets (Latin, Greek, Hebrew), the mathematical language uses many special symbols invented over the past few centuries.

2. Addition and subtraction signs

The history of mathematical notation begins with the Paleolithic. Stones and bones with notches used for counting date back to this time. Most famous example - Ishango bone. The famous bone from Ishango (Congo) dating back to approximately 20 thousand years ago new era, proves that already at that time man performed quite complex mathematical operations. The notches on the bones were used for addition and were applied in groups, symbolizing the addition of numbers.

IN Ancient Egypt there was already a much more advanced notation system. For example, inAhmes papyrusThe addition symbol uses an image of two legs walking forward across the text, and the subtraction symbol uses two legs walking backward.The ancient Greeks indicated addition by writing side by side, but occasionally used the slash symbol “/” and a semi-elliptical curve for subtraction.

The symbols for the arithmetic operations of addition (plus “+’’) and subtraction (minus “-‘’) are so common that we almost never think about the fact that they did not always exist. The origin of these symbols is unclear. One version is that they were previously used in trading as signs of profit and loss.

It is also believed that our signcomes from one form of the word “et”, which means “and” in Latin. Expression a+b it was written in Latin like this: a et b . Gradually, due to frequent use, from the sign " et " remains only " t "which, over time, turned into "+ ". The first person who may have used the signas an abbreviation for et, was the astronomer Nicole d'Orem (author of The Book of the Sky and the World’’ - “Books of Heaven and World”) in the middle of the fourteenth century.

At the end of the fifteenth century, the French mathematician Chiquet (1484) and the Italian Pacioli (1494) used “'' or " ’’ (denoting “plus”) for addition and “'' or " '' (denoting "minus") for subtraction.

The subtraction notation was more confusing because instead of simple sign “ ” in German, Swiss and Dutch books they sometimes used the symbol “÷’’, which we now use to denote division. Several seventeenth-century books (such as Descartes and Mersenne) use two dots “∙ ∙’’ or three dots “∙ ∙ ∙’’ to indicate subtraction.

First use of the modern algebraic symbol “” refers to a German algebra manuscript from 1481 that was found in the Dresden library. In a Latin manuscript from the same time (also from the Dresden library), there are both characters: "" And " - " . Systematic use of signs "" and " - " for addition and subtraction are found inJohann Widmann. The German mathematician Johann Widmann (1462-1498) was the first to use both signs to mark the presence and absence of students in his lectures. True, there is information that he “borrowed” these signs from a little-known professor at the University of Leipzig. In 1489, he published the first printed book in Leipzig (Mercantile Arithmetic - “Commercial Arithmetic”), in which both signs were present And , in the work “A quick and pleasant account for all merchants” (c. 1490)

As a historical curiosity, it is worth noting that even after the adoption of the signnot everyone used this symbol. Widmann himself introduced it as the Greek cross(the sign we use today), in which the horizontal stroke is sometimes slightly longer than the vertical one. Some mathematicians, such as Record, Harriot and Descartes, used the same sign. Others (such as Hume, Huygens, and Fermat) used the Latin cross "†", sometimes positioned horizontally, with a crossbar at one end or the other. Finally, some (such as Halley) used more decorative look « ».

3.Equal sign

The equal sign in mathematics and other exact sciences is written between two expressions that are identical in size. Diophantus was the first to use the equal sign. He designated equality with the letter i (from the Greek isos - equal). INancient and medieval mathematicsequality was indicated verbally, for example, est egale, or they used the abbreviation “ae” from the Latin aequalis - “equal”. Other languages ​​also used the first letters of the word “equal,” but this was not generally accepted. The equal sign "=" was introduced in 1557 by a Welsh physician and mathematicianRobert Record(Recorde R., 1510-1558). In some cases, the mathematical symbol for denoting equality was the symbol II. Record introduced the symbol “=’’ with two equal horizontal parallel lines, much longer than those used today. The English mathematician Robert Record was the first to use the equality symbol, arguing with the words: “no two objects can be more equal to each other than two parallel segments.” But still inXVII centuryRene Descartesused the abbreviation “ae’’.Francois VietThe equal sign denoted subtraction. For some time, the spread of the Record symbol was hampered by the fact that the same symbol was used to indicate the parallelism of straight lines; In the end, it was decided to make the parallelism symbol vertical. The sign became widespread only after the work of Leibniz at the turn of the 17th-18th centuries, that is, more than 100 years after the death of the person who first used it for this purpose.Robert Record. There are no words on his tombstone - just an equal sign carved into it.

The related symbols for denoting the approximate equality "≈" and the identity "≡" are very young - the first was introduced in 1885 by Günther, the second in 1857Riemann

4. Multiplication and division signs

The multiplication sign in the form of a cross ("x") was introduced by an Anglican priest-mathematicianWilliam Oughtred V 1631. Before him, the letter M was used for the multiplication sign, although other notations were also proposed: the rectangle symbol (Erigon, ), asterisk ( Johann Rahn, ).

Later Leibnizreplaced the cross with a dot (end17th century), so as not to confuse it with the letter x ; before him, such symbolism was found amongRegiomontana (15th century) and English scientistThomas Herriot (1560-1621).

To indicate the action of divisionEditpreferred slash. The colon began to denote divisionLeibniz. Before them, the letter D was also often used. Starting withFibonacci, the fraction line, which was used in Arabic works, is also used. Division in the form obelus ("÷") introduced by a Swiss mathematicianJohann Rahn(c. 1660)

5. Percent sign.

A hundredth of a whole, taken as a unit. The word “percent” itself comes from the Latin “pro centum”, which means “per hundred”. In 1685, the book “Manual of Commercial Arithmetic” by Mathieu de la Porte (1685) was published in Paris. In one place they talked about percentages, which were then designated “cto” (short for cento). However, the typesetter mistook this "cto" for a fraction and printed "%". So, due to a typo, this sign came into use.

6.Infinity sign

The current infinity symbol "∞" came into useJohn Wallis in 1655. John Wallispublished a large treatise "Arithmetic of the Infinite" (lat.Arithmetica Infinitorum sive Nova Methodus Inquirendi in Curvilineorum Quadraturam, aliaque Difficiliora Matheseos Problemata), where he entered the symbol he inventedinfinity. It is still not known why he chose this particular sign. One of the most authoritative hypotheses connects the origin of this symbol with the Latin letter "M", which the Romans used to represent the number 1000.The infinity symbol was named "lemniscus" (Latin ribbon) by the mathematician Bernoulli some forty years later.

Another version says that the figure-eight figure conveys the main property of the concept of “infinity”: movement endlessly . Along the lines of the number 8 you can move endlessly, like on a bicycle track. In order not to confuse the entered sign with the number 8, mathematicians decided to place it horizontally. Happened. This notation has become standard for all mathematics, not just algebra. Why is infinity not represented by zero? The answer is obvious: no matter how you turn the number 0, it will not change. Therefore, the choice fell on 8.

Another option is a snake devouring its own tail, which one and a half thousand years BC in Egypt symbolized various processes that had no beginning or end.

Many believe that the Möbius strip is the progenitor of the symbolinfinity, because the infinity symbol was patented after the invention of the Mobius strip device (named after the nineteenth-century mathematician Moebius). A Möbius strip is a strip of paper that is curved and connected at its ends, forming two spatial surfaces. However, according to available historical information the infinity symbol began to be used to represent infinity two centuries before the discovery of the Möbius strip

7. Signs angle a and perpendicular sti

Symbols " corner" And " perpendicular"invented in 1634French mathematicianPierre Erigon. His perpendicularity symbol was inverted, resembling the letter T. The angle symbol resembled an icon, gave it a modern formWilliam Oughtred ().

8. Sign parallelism And

Symbol " parallelism» known since ancient times, it was usedHeron And Pappus of Alexandria. At first the symbol was similar to the current equals sign, but with the advent of the latter, to avoid confusion, the symbol was turned vertically (Edit(1677), Kersey (John Kersey ) and other mathematicians of the 17th century)

9. Pi

The generally accepted designation of a number equal to the ratio of the circumference of a circle to its diameter (3.1415926535...) was first formedWilliam Jones V 1706, taking the first letter of the Greek words περιφέρεια -circle and περίμετρος - perimeter, that is, the circumference. I liked this abbreviation.Euler, whose works firmly established the designation.

10. Sine and cosine

The appearance of sine and cosine is interesting.

Sinus from Latin - sinus, cavity. But this name has a long history. Indian mathematicians made great progress in trigonometry around the 5th century. The word “trigonometry” itself did not exist; it was introduced by Georg Klügel in 1770.) What we now call sine roughly corresponds to what the Hindus called ardha-jiya, translated as half-string (i.e. half-chord). For brevity, they simply called it jiya (string). When the Arabs translated the works of the Hindus from Sanskrit, they did not translate the “string” into Arabic, but simply transcribed the word in Arabic letters. The result was a jiba. But since in syllabic Arabic writing short vowels are not indicated, what really remains is j-b, which is similar to another Arabic word - jaib (hollow, bosom). When Gerard of Cremona translated the Arabs into Latin in the 12th century, he translated the word as sinus, which in Latin also means sinus, depression.

The cosine appeared automatically, because the Hindus called it koti-jiya, or ko-jiya for short. Koti is the curved end of a bow in Sanskrit.Modern shorthand notations and introduced William Oughtredand enshrined in the works Euler.

The designation tangent/cotangent has a much later origin (the English word tangent comes from the Latin tangere - to touch). And even now there is no unified designation - in some countries the designation tan is more often used, in others - tg

11. Abbreviation “What was required to be proven” (etc.)

« Quod erat demonstrandum "(quol erat lamonstranlum).
The Greek phrase means “what needed to be proved,” and the Latin means “what needed to be shown.” This formula ends every mathematical argument of the great Greek mathematician Ancient Greece Euclid (III century BC). Translated from Latin - which is what needed to be proven. In medieval scientific treatises this formula was often written in abbreviated form: QED.

12. Mathematical notation.

Symbols	History of symbols
	The plus and minus signs were apparently invented in the German mathematical school of “Kossists” (that is, algebraists). They are used in Johann Widmann's Arithmetic published in 1489. Previously, addition was denoted by the letter p (plus) or the Latin word et (conjunction “and”), and subtraction by the letter m (minus). For Widmann, the plus symbol replaces not only addition, but also the conjunction “and.” The origin of these symbols is unclear, but most likely they were previously used in trading as indicators of profit and loss. Both symbols almost instantly became common in Europe - with the exception of Italy.
× ∙	The multiplication sign was introduced in 1631 by William Oughtred (England) in the form of an oblique cross. Before him, the letter M was used. Later, Leibniz replaced the cross with a dot (late 17th century) so as not to confuse it with the letter x; before him, such symbolism was found in Regiomontan (XV century) and the English scientist Thomas Harriot (1560-1621).
/ : ÷	Oughtred preferred the slash. Leibniz began to denote division with a colon. Before them, the letter D was also often used. Starting with Fibonacci, the fraction line, which was used in Arabic writings, is also used. In England and the USA, the symbol ÷ (obelus), which was proposed by Johann Rahn and John Pell in the middle of the 17th century, became widespread.
=	The equal sign was proposed by Robert Record (1510-1558) in 1557. He explained that there is nothing more equal in the world than two parallel segments of the same length. In continental Europe, the equal sign was introduced by Leibniz.
	Comparative signs were introduced by Thomas Herriot in his work, published posthumously in 1631. Before him they wrote with the words: more, less.
%	The percentage symbol appears in the middle of the 17th century in several sources, its origin is unclear. There is a hypothesis that it arose from a typist's mistake, who typed the abbreviation cto (cento, hundredth) as 0/0. It is more likely that this is a cursive commercial icon that appeared about 100 years earlier.
√	The root sign was first used by the German mathematician Christoph Rudolf, from the Cossist school, in 1525. This symbol comes from the stylized first letter of the word radix (root). At first there was no line above the radical expression; it was later introduced by Descartes for a different purpose (instead of parentheses), and this feature soon merged with the root sign.
a n	Exponentiation. The modern notation of the exponent was introduced by Descartes in his “Geometry” (1637), however, only for natural powers greater than 2. Later, Newton extended this form of notation to negative and fractional exponents (1676).
()	Parentheses appeared in Tartaglia (1556) for radical expressions, but most mathematicians preferred to underline the expression being highlighted instead of parentheses. Leibniz introduced brackets into general use.
	The sum sign was introduced by Euler in 1755
	The product symbol was introduced by Gauss in 1812
i	The letter i as an imaginary unit code:proposed by Euler (1777), who took for this the first letter of the word imaginarius (imaginary).
π	The generally accepted designation for the number 3.14159... was formed by William Jones in 1706, taking the first letter of the Greek words περιφέρεια - circle and περίμετρος - perimeter, that is, the circumference.
	Leibniz derived his notation for the integral from the first letter of the word “Summa”.
y"	The short notation of a derivative by a prime goes back to Lagrange.
	The symbol of the limit appeared in 1787 by Simon Lhuillier (1750-1840).
	The infinity symbol was invented by Wallis and published in 1655.

13. Conclusion

Mathematical science is essential for a civilized society. Mathematics is contained in all sciences. Mathematical language is mixed with the language of chemistry and physics. But we still understand it. We can say that we begin to learn the language of mathematics together with our native speech. This is how mathematics has inextricably entered our lives. Thanks to the mathematical discoveries of the past, scientists create new technologies. The surviving discoveries make it possible to solve complex mathematical problems. And the ancient mathematical language is clear to us, and discoveries are interesting to us. Thanks to mathematics, Archimedes, Plato, and Newton discovered physical laws. We study them at school. In physics there are also symbols and terms inherent in physical science. But mathematical language is not lost among physical formulas. On the contrary, these formulas cannot be written without knowledge of mathematics. History preserves knowledge and facts for future generations. Further study of mathematics is necessary for new discoveries. To use presentation previews, create an account for yourself ( account) Google and log in: https://accounts.google.com

Slide captions:

Mathematical symbols The work was completed by a 7th grade student of school No. 574 Balagin Victor

Symbol (Greek symbolon - sign, omen, password, emblem) is a sign that is associated with the objectivity it denotes in such a way that the meaning of the sign and its object are represented only by the sign itself and are revealed only through its interpretation. Signs are mathematical symbols designed to record mathematical concepts, sentences and calculations.

Ishango Bone Part of the Ahmes Papyrus

+ − Plus and minus signs. Addition was indicated by the letter p (plus) or the Latin word et (conjunction “and”), and subtraction by the letter m (minus). The expression a + b was written in Latin like this: a et b.

Subtraction notation. ÷ ∙ ∙ or ∙ ∙ ∙ René Descartes Maren Mersenne

A page from the book by Johann Widmann. In 1489, Johann Widmann published the first printed book in Leipzig (Mercantile Arithmetic - “Commercial Arithmetic”), in which both + and - signs were present.

Addition notation. Christiaan Huygens David Hume Pierre de Fermat Edmund (Edmond) Halley

Equal sign Diophantus was the first to use the equal sign. He designated equality with the letter i (from the Greek isos - equal).

Equal sign Proposed in 1557 by the English mathematician Robert Record “No two objects can be more equal to each other than two parallel segments.” In continental Europe, the equal sign was introduced by Leibniz

× ∙ The multiplication sign was introduced in 1631 by William Oughtred (England) in the form of an oblique cross. Leibniz replaced the cross with a dot (late 17th century) so as not to confuse it with the letter x. William Oughtred Gottfried Wilhelm Leibniz

Percent. Mathieu de la Porte (1685). A hundredth of a whole, taken as a unit. “percent” - “pro centum”, which means “per hundred”. "cto" (short for cento). The typist mistook "cto" for a fraction and typed "%".

Infinity. John Wallis John Wallis introduced the symbol he invented in 1655. The serpent devouring its tail symbolized various processes that have no beginning or end.

The infinity symbol began to be used to represent infinity two centuries before the discovery of the Möbius strip. A Möbius strip is a strip of paper that is curved and connected at its ends, forming two spatial surfaces. August Ferdinand Mobius

Angle and perpendicular. The symbols were invented in 1634 by the French mathematician Pierre Erigon. Erigon's angle symbol resembled an icon. The perpendicularity symbol has been inverted, resembling the letter T. These signs were given their modern form by William Oughtred (1657).

Parallelism. The symbol was used by Heron of Alexandria and Pappus of Alexandria. At first the symbol was similar to the current equals sign, but with the advent of the latter, to avoid confusion, the symbol was turned vertically. Heron of Alexandria

Pi. π ≈ 3.1415926535... William Jones in 1706 π εριφέρεια is the circle and π ερίμετρος is the perimeter, that is, the circumference. Euler liked this abbreviation, whose works finally consolidated the designation. William Jones

sin Sine and cosine cos Sinus (from Latin) – sinus, cavity. Kochi-jiya, or ko-jiya for short. Coty - the curved end of a bow Modern shorthand notation was introduced by William Oughtred and established in the works of Euler. “Arha-jiva” - among the Indians - “half-string” Leonard Euler William Oughtred

What was required to be proven (etc.) “Quod erat demonstrandum” QED. This formula ends every mathematical argument of the great mathematician of Ancient Greece, Euclid (3rd century BC).

The ancient mathematical language is clear to us. In physics there are also symbols and terms inherent in physical science. But mathematical language is not lost among physical formulas. On the contrary, these formulas cannot be written without knowledge of mathematics.

The course uses geometric language, composed of notations and symbols adopted in a mathematics course (in particular, in the new geometry course in high school).

The whole variety of designations and symbols, as well as the connections between them, can be divided into two groups:

group I - designations of geometric figures and relationships between them;

group II designations of logical operations that form the syntactic basis of the geometric language.

Below is a complete list of math symbols used in this course. Particular attention is paid to the symbols that are used to indicate the projections of geometric figures.

Group I

SYMBOLS INDICATING GEOMETRIC FIGURES AND RELATIONS BETWEEN THEM

A. Designation of geometric figures

1. A geometric figure is designated - F.

2. Points are designated in capital letters Latin alphabet or Arabic numerals:

A, B, C, D, ... , L, M, N, ...

1,2,3,4,...,12,13,14,...

3. Lines arbitrarily located in relation to the projection planes are designated by lowercase letters of the Latin alphabet:

a, b, c, d, ... , l, m, n, ...

Level lines are designated: h - horizontal; f- front.

The following notations are also used for straight lines:

(AB) - a straight line passing through points A and B;

[AB) - ray with beginning at point A;

[AB] - a straight line segment bounded by points A and B.

4. Surfaces are designated by lowercase letters of the Greek alphabet:

α, β, γ, δ,...,ζ,η,ν,...

To emphasize the way a surface is defined, the geometric elements by which it is defined should be indicated, for example:

α(a || b) - the plane α is determined by parallel lines a and b;

β(d 1 d 2 gα) - the surface β is determined by the guides d 1 and d 2, the generator g and the plane of parallelism α.

5. Angles are indicated:

∠ABC - angle with vertex at point B, as well as ∠α°, ∠β°, ... , ∠φ°, ...

6. Angular: the value (degree measure) is indicated by the sign, which is placed above the angle:

The magnitude of the angle ABC;

The magnitude of the angle φ.

A right angle is marked with a square with a dot inside

7. Distances between geometric shapes are indicated by two vertical segments - ||.

For example:

|AB| - the distance between points A and B (length of segment AB);

|Aa| - distance from point A to line a;

|Aα| - distances from point A to surface α;

|ab| - distance between lines a and b;

|αβ| distance between surfaces α and β.

8. For projection planes, the following designations are accepted: π 1 and π 2, where π 1 is the horizontal projection plane;

π 2 - frontal projection plane.

When replacing projection planes or introducing new planes, the latter are designated π 3, π 4, etc.

9. The projection axes are designated: x, y, z, where x is the abscissa axis; y - ordinate axis; z - applicate axis.

Monge's constant straight line diagram is denoted by k.

10. Projections of points, lines, surfaces, any geometric figure are indicated by the same letters (or numbers) as the original, with the addition of a superscript corresponding to the projection plane on which they were obtained:

A", B", C", D", ... , L", M", N", horizontal projections of points; A", B", C", D", ... , L", M" , N", ... frontal projections of points; a" , b" , c" , d" , ... , l", m" , n" , - horizontal projections of lines; a" , b" , c" , d" , ... , l" , m " , n" , ... frontal projections of lines; α", β", γ", δ",...,ζ",η",ν",... horizontal projections of surfaces; α", β", γ", δ",...,ζ" ,η",ν",... frontal projections of surfaces.

11. Traces of planes (surfaces) are designated by the same letters as horizontal or frontal, with the addition of the subscript 0α, emphasizing that these lines lie in the projection plane and belong to the plane (surface) α.

So: h 0α - horizontal trace of the plane (surface) α;

f 0α - frontal trace of the plane (surface) α.

12. Traces of straight lines (lines) are indicated in capital letters, with which the words begin that define the name (in Latin transcription) of the projection plane that the line intersects, with a subscript indicating membership in the line.

For example: H a - horizontal trace of a straight line (line) a;

F a - frontal trace of straight line (line) a.

13. The sequence of points, lines (any figure) is marked with subscripts 1,2,3,..., n:

A 1, A 2, A 3,..., A n;

a 1 , a 2 , a 3 ,...,a n ;

α 1, α 2, α 3,...,α n;

Ф 1, Ф 2, Ф 3,..., Ф n, etc.

The auxiliary projection of a point, obtained as a result of transformation to obtain the actual value of a geometric figure, is denoted by the same letter with a subscript 0:

A 0 , B 0 , C 0 , D 0 , ...

Axonometric projections

14. Axonometric projections of points, lines, surfaces are denoted by the same letters as nature with the addition of a superscript 0:

A 0, B 0, C 0, D 0, ...

1 0 , 2 0 , 3 0 , 4 0 , ...

a 0 , b 0 , c 0 , d 0 , ...

α 0 , β 0 , γ 0 , δ 0 , ...

15. Secondary projections are indicated by adding a superscript 1:

A 1 0, B 1 0, C 1 0, D 1 0, ...

1 1 0 , 2 1 0 , 3 1 0 , 4 1 0 , ...

a 1 0 , b 1 0 , c 1 0 , d 1 0 , ...

α 1 0 , β 1 0 , γ 1 0 , δ 1 0 , ...

To make it easier to read the drawings in the textbook, several colors are used when designing the illustrative material, each of which has a certain semantic meaning: black lines (dots) indicate the original data; green color used for lines of auxiliary graphic constructions; red lines (dots) show the results of constructions or those geometric elements to which special attention should be paid.

B. Symbols denoting relationships between geometric figures

No. by por.	Designation	Content	Example of symbolic notation
1	≡	Match	(AB)≡(CD) - a straight line passing through points A and B, coincides with the line passing through points C and D
2	≅	Congruent	∠ABC≅∠MNK - angle ABC is congruent to angle MNK
3	∼	Similar	ΔАВС∼ΔMNK - triangles АВС and MNK are similar
4	||	Parallel	α||β - plane α is parallel to plane β
5	⊥	Perpendicular	a⊥b - straight lines a and b are perpendicular
6		Crossbreed	c d - straight lines c and d intersect
7		Tangents	t l - line t is tangent to line l. βα - plane β tangent to surface α
8	→	Displayed	F 1 →F 2 - figure F 1 is mapped to figure F 2
9	S	Projection Center. If the projection center is an improper point, then its position is indicated by an arrow, indicating the direction of projection	-
10	s	Projection direction	-
11	P	Parallel projection	р s α Parallel projection - parallel projection onto the α plane in the s direction

B. Set-theoretic notation

No. by por.	Designation	Content	Example of symbolic notation	Example of symbolic notation in geometry
1	M,N	Sets	-	-
2	A,B,C,...	Elements of the set	-	-
3	{ ... }	Comprises...	Ф(A, B, C,...)	Ф(A, B, C,...) - figure Ф consists of points A, B, C, ...
4	∅	Empty set	L - ∅ - the set L is empty (does not contain elements)	-
5	∈	Belongs to, is an element	2∈N (where N is the set natural numbers) - the number 2 belongs to the set N	A ∈ a - point A belongs to line a (point A lies on line a)
6	⊂	Includes, contains	N⊂M - set N is part (subset) of set M of all rational numbers	a⊂α - straight line a belongs to the plane α (understood in the sense: the set of points of the line a is a subset of the points of the plane α)
7	∪	An association	C = A U B - set C is a union of sets A and B; (1, 2. 3, 4.5) = (1,2,3)∪(4.5)	ABCD = ∪ [ВС] ∪ - broken line, ABCD is combining segments [AB], [BC],
8	∩	Intersection of many	M=K∩L - the set M is the intersection of the sets K and L (contains elements belonging to both the set K and the set L). M ∩ N = ∅ - the intersection of the sets M and N is empty set (sets M and N do not have common elements)	a = α ∩ β - straight line a is the intersection planes α and β a ∩ b = ∅ - straight lines a and b do not intersect (do not have common points)

Group II SYMBOLS INDICATING LOGICAL OPERATIONS

No. by por.	Designation	Content	Example of symbolic notation
1	∧	Conjunction of sentences; corresponds to the conjunction "and". A sentence (p∧q) is true if and only if p and q are both true	α∩β = (К:K∈α∧K∈β) The intersection of surfaces α and β is a set of points (line), consisting of all those and only those points K that belong to both the surface α and the surface β
2	∨	Disjunction of sentences; matches the conjunction "or". Sentence (p∨q) true when at least one of the sentences p or q is true (that is, either p or q, or both).	-
3	⇒	Implication is a logical consequence. The sentence p⇒q means: “if p, then q”	(a||c∧b||c)⇒a||b. If two lines are parallel to a third, then they are parallel to each other
4	⇔	The sentence (p⇔q) is understood in the sense: “if p, then also q; if q, then also p”	А∈α⇔А∈l⊂α. A point belongs to a plane if it belongs to some line belonging to this plane. The converse statement is also true: if a point belongs to a certain line, belonging to the plane, then it belongs to the plane itself
5	∀	The general quantifier reads: for everyone, for everyone, for anyone. The expression ∀(x)P(x) means: “for every x: the property P(x) holds”	∀(ΔАВС)( = 180°) For any (for any) triangle, the sum of the values ​​of its angles at vertices equals 180°
6	∃	The existential quantifier reads: exists. The expression ∃(x)P(x) means: “there is an x ​​that has the property P(x)”	(∀α)(∃a).For any plane α there is a straight line a that does not belong to the plane α and parallel to the plane α
7	∃1	The quantifier of the uniqueness of existence, reads: there is only one (-i, -th)... The expression ∃1(x)(Рх) means: “there is only one (only one) x, having the property Px"	(∀ A, B)(A≠B)(∃1a)(a∋A, B) For any two different points A and B, there is a unique straight line a, passing through these points.
8	(Px)	Negation of the statement P(x)	ab(∃α)(α⊃a, b).If lines a and b intersect, then there is no plane a that contains them
9	\	Negation of the sign	≠ -segment [AB] is not equal to segment .a?b - line a is not parallel to line b

of two), 3 > 2 (three is more than two), etc.

The development of mathematical symbolism was closely related to the general development of concepts and methods of mathematics. First Mathematical signs there were signs to depict numbers - numbers, the emergence of which, apparently, preceded writing. The most ancient numbering systems - Babylonian and Egyptian - appeared as early as 3 1/2 millennium BC. e.

First Mathematical signs for arbitrary quantities appeared much later (starting from the 5th-4th centuries BC) in Greece. Quantities (areas, volumes, angles) were depicted in the form of segments, and the product of two arbitrary homogeneous quantities was depicted in the form of a rectangle built on the corresponding segments. In "Principles" Euclid (3rd century BC) quantities are denoted by two letters - the initial and final letters of the corresponding segment, and sometimes just one. U Archimedes (3rd century BC) the latter method becomes common. Such a designation contained possibilities for the development of letter calculus. However, in classical ancient mathematics, letter calculus was not created.

The beginnings of letter representation and calculus appeared in the late Hellenistic era as a result of the liberation of algebra from geometric form. Diophantus (probably 3rd century) recorded unknown ( X) and its degree with the following signs:

[ - from the Greek term dunamiV (dynamis - force), denoting the square of the unknown, - from the Greek cuboV (k_ybos) - cube]. To the right of the unknown or its powers, Diophantus wrote coefficients, for example 3 x 5 was depicted

(where = 3). When adding, Diophantus attributed the terms to each other, and used a special sign for subtraction; Diophantus denoted equality with the letter i [from the Greek isoV (isos) - equal]. For example, the equation

(x 3 + 8x) - (5x 2 + 1) =X

Diophantus would have written it like this:

(Here

means that the unit does not have a multiplier in the form of a power of the unknown).

Several centuries later, the Indians introduced various Mathematical signs for several unknowns (abbreviations for the names of colors denoting unknowns), a square, square root, the number to be subtracted. So, the equation

3X 2 + 10x - 8 = x 2 + 1

In recording Brahmagupta (7th century) would look like:

Ya va 3 ya 10 ru 8

Ya va 1 ya 0 ru 1

(ya - from yawat - tawat - unknown, va - from varga - square number, ru - from rupa - rupee coin - free term, a dot over the number means the subtracted number).

The creation of modern algebraic symbolism dates back to the 14th-17th centuries; it was determined by the successes of practical arithmetic and the study of equations. In various countries they spontaneously appear Mathematical signs for some actions and for powers of unknown magnitude. Many decades and even centuries pass before one or another convenient symbol is developed. So, at the end of 15 and. N. Shuke and L. Pacioli used addition and subtraction signs

(from Latin plus and minus), German mathematicians introduced modern + (probably an abbreviation of Latin et) and -. Back in the 17th century. you can count about a dozen Mathematical signs for the multiplication action.

There were also different Mathematical signs unknown and its degrees. In the 16th - early 17th centuries. more than ten notations competed for the square of the unknown alone, e.g. se(from census - a Latin term that served as a translation of the Greek dunamiV, Q(from quadratum), , A (2), , Aii, aa, a 2 etc. Thus, the equation

x 3 + 5 x = 12

the Italian mathematician G. Cardano (1545) would have the form:

from the German mathematician M. Stiefel (1544):

from the Italian mathematician R. Bombelli (1572):

French mathematician F. Vieta (1591):

from the English mathematician T. Harriot (1631):

In the 16th and early 17th centuries. equal signs and brackets are used: square (R. Bombelli , 1550), round (N. Tartaglia, 1556), figured (F. Viet, 1593). In the 16th century modern look accepts notation of fractions.

A significant step forward in the development of mathematical symbolism was the introduction by Viet (1591) Mathematical signs for arbitrary constant quantities in the form of capital consonant letters of the Latin alphabet B, D, which gave him the opportunity to write down for the first time algebraic equations with arbitrary coefficients and operate with them. Viet depicted unknowns with vowels in capital letters A, E,... For example, Viet's recording

In our symbols it looks like this:

x 3 + 3bx = d.

Viet was the creator of algebraic formulas. R. Descartes (1637) gave the signs of algebra a modern look, denoting unknowns with the last letters of Lat. alphabet x, y, z, and arbitrary data values ​​- with initial letters a, b, c. The current record of the degree belongs to him. Descartes' notations had a great advantage over all previous ones. Therefore, they soon received universal recognition.

Further development Mathematical signs was closely connected with the creation of infinitesimal analysis, for the development of the symbolism of which the basis was already largely prepared in algebra.

Dates of origin of some mathematical symbols

sign	meaning	Who entered	When entered
Signs of individual objects
¥	infinity	J. Wallis	1655
e	base of natural logarithms	L. Euler	1736
p	ratio of circumference to diameter	W. Jones L. Euler	1706
i	square root of -1	L. Euler	1777 (printed 1794)
i j k	unit vectors, unit vectors	W. Hamilton	1853
P(a)	angle of parallelism	N.I. Lobachevsky	1835
Signs of variable objects
x,y,z	unknown or variable quantities	R. Descartes	1637
r	vector	O. Cauchy	1853
Individual Operations Signs
+	addition	German mathematicians	Late 15th century
–	subtraction
´	multiplication	W. Outred	1631
×	multiplication	G. Leibniz	1698
:	division	G. Leibniz	1684
a 2 , a 3 ,…, a n	degrees	R. Descartes	1637
		I. Newton	1676
	roots	K. Rudolph	1525
		A. Girard	1629
Log	logarithm	I. Kepler	1624
log		B. Cavalieri	1632
sin	sinus	L. Euler	1748
cos	cosine
tg	tangent	L. Euler	1753
arc.sin	arcsine	J. Lagrange	1772
Sh	hyperbolic sine	V. Riccati	1757
Ch	hyperbolic cosine
dx, ddx, …	differential	G. Leibniz	1675 (printed 1684)
d 2 x, d 3 x,…
	integral	G. Leibniz	1675 (printed 1686)
	derivative	G. Leibniz	1675
¦¢x	derivative	J. Lagrange	1770, 1779
y'
¦¢(x)
Dx	difference	L. Euler	1755
	partial derivative	A. Legendre	1786
	definite integral	J. Fourier	1819-22
	sum	L. Euler	1755
P	work	K. Gauss	1812
!	factorial	K. Crump	1808
|x|	module	K. Weierstrass	1841
lim	limit	W. Hamilton, many mathematicians	1853, early 20th century
lim
n = ¥
lim
n ® ¥
x	zeta function	B. Riemann	1857
G	gamma function	A. Legendre	1808
IN	beta function	J. Binet	1839
D	delta (Laplace operator)	R. Murphy	1833
Ñ	nabla (Hamilton cameraman)	W. Hamilton	1853
Signs of variable operations
jx	function	I. Bernouli	1718
f(x)		L. Euler	1734
Signs of individual relationships
=	equality	R. Record	1557
>	more	T. Garriott	1631
<	less
º	comparability	K. Gauss	1801
	parallelism	W. Outred	1677
^	perpendicularity	P. Erigon	1634

AND. Newton in his method of fluxions and fluents (1666 and subsequent years) he introduced signs for successive fluxions (derivatives) of a quantity (in the form

and for an infinitesimal increment o. Somewhat earlier J. Wallis (1655) proposed the infinity sign ¥.

The creator of modern symbolism of differential and integral calculus is G. Leibniz. In particular, he owns the currently used Mathematical signs differentials

dx,d 2 x, d 3 x

and integral

Enormous credit for creating the symbolism of modern mathematics belongs to L. Euler. He introduced (1734) into general use the first sign of a variable operation, namely the sign of the function f(x) (from Latin functio). After Euler's work, the signs for many individual functions, such as trigonometric functions, became standard. Euler is the author of the notation for the constants e(base of natural logarithms, 1736), p [probably from Greek perijereia (periphereia) - circle, periphery, 1736], imaginary unit

(from the French imaginaire - imaginary, 1777, published 1794).

In the 19th century the role of symbolism is increasing. At this time, the signs of the absolute value |x| appear. (TO. Weierstrass, 1841), vector (O. Cauchy, 1853), determinant

(A. Cayley, 1841), etc. Many theories that arose in the 19th century, for example tensor calculus, could not be developed without suitable symbolism.

Along with the specified standardization process Mathematical signs in modern literature one can often find Mathematical signs, used by individual authors only within the scope of this study.

From the point of view of mathematical logic, among Mathematical signs The following main groups can be outlined: A) signs of objects, B) signs of operations, C) signs of relations. For example, the signs 1, 2, 3, 4 represent numbers, that is, objects studied by arithmetic. The addition sign + by itself does not represent any object; it receives subject content when it is indicated which numbers add up: the notation 1 + 3 represents the number 4. The sign > (greater than) is a sign of the relationship between numbers. The relation sign receives a completely definite content when it is indicated between which objects the relation is considered. To the listed three main groups Mathematical signs adjacent to the fourth: D) auxiliary signs that establish the order of combination of the main signs. A sufficient idea of ​​such signs is given by brackets indicating the order of actions.

Signs of each three groups A), B) and C) are of two kinds: 1) individual signs of well-defined objects, operations and relations, 2) general signs of “non-variable” or “unknown” objects, operations and relations.

Examples of signs of the first kind can serve (see also table):

A 1) Designations of natural numbers 1, 2, 3, 4, 5, 6, 7, 8, 9; transcendental numbers e and p; imaginary unit i.

B 1) Signs of arithmetic operations +, -, ·, ´,:; root extraction, differentiation

signs of the sum (union) È and the product (intersection) Ç of sets; this also includes the signs of individual functions sin, tg, log, etc.

1) Equal and inequality signs =, >,<, ¹, знаки параллельности || и перпендикулярности ^, знаки принадлежности Î элемента некоторому множеству и включения Ì одного множества в другое и т.п.

Signs of the second kind depict arbitrary objects, operations and relations of a certain class or objects, operations and relations that are subject to some pre-agreed conditions. For example, when writing the identity ( a + b)(a - b) = a 2 -b 2 letters A And b represent arbitrary numbers; when studying functional dependence at = X 2 letters X And y - arbitrary numbers connected by a given relationship; when solving the equation

X denotes any number that satisfies this equation (as a result of solving this equation, we learn that only two possible values ​​+1 and -1 correspond to this condition).

From a logical point of view, it is legitimate to call such general signs signs of variables, as is customary in mathematical logic, without being afraid of the fact that the “domain of change” of a variable may turn out to consist of one single object or even “empty” (for example, in the case of equations , without a solution). Further examples of this type of signs can be:

A 2) Designations of points, lines, planes and more complex geometric figures with letters in geometry.

B 2) Designations f, , j for functions and operator calculus notation, when with one letter L represent, for example, an arbitrary operator of the form:

Notations for “variable relations” are less common; they are used only in mathematical logic (see. Algebra of logic ) and in relatively abstract, mostly axiomatic, mathematical studies.

Lit.: Cajori., A history of mathematical notations, v. 1-2, Chi., 1928-29.

Article about the word " Mathematical signs" in the Great Soviet Encyclopedia was read 39,764 times

As you know, mathematics loves precision and brevity - it’s not without reason that a single formula can, in verbal form, take up a paragraph, and sometimes even a whole page of text. Thus, graphical elements used throughout the world in science are designed to increase the speed of writing and the compactness of data presentation. In addition, standardized graphic images can be recognized by a native speaker of any language who has basic knowledge in the relevant field.

The history of mathematical signs and symbols goes back many centuries - some of them were invented randomly and were intended to indicate other phenomena; others became the product of the activities of scientists who purposefully form an artificial language and are guided exclusively by practical considerations.

Plus and minus

The history of the origin of symbols denoting the simplest arithmetic operations is not known for certain. However, there is a fairly plausible hypothesis for the origin of the plus sign, which looks like crossed horizontal and vertical lines. In accordance with it, the addition symbol originates in the Latin union et, which is translated into Russian as “and”. Gradually, in order to speed up the writing process, the word was shortened to a vertically oriented cross, resembling the letter t. The earliest reliable example of such a contraction dates back to the 14th century.

The generally accepted minus sign appeared, apparently, later. In the 14th and even 15th centuries, a number of symbols were used in scientific literature to denote the operation of subtraction, and only by the 16th century did “plus” and “minus” in their modern form begin to appear together in mathematical works.

Multiplication and division

Oddly enough, the mathematical signs and symbols for these two arithmetic operations are not completely standardized today. A popular symbol for multiplication is the diagonal cross proposed by the mathematician Oughtred in the 17th century, which can be seen, for example, on calculators. In mathematics lessons at school, the same operation is usually represented as a point - this method was proposed by Leibniz in the same century. Another representation method is an asterisk, which is most often used in computer representation of various calculations. It was proposed to use it in the same 17th century by Johann Rahn.

For the division operation, a slash sign (proposed by Oughtred) and a horizontal line with dots above and below are provided (the symbol was introduced by Johann Rahn). The first designation option is more popular, but the second is also quite common.

Mathematical signs and symbols and their meanings sometimes change over time. However, all three methods of graphically representing multiplication, as well as both methods for division, are to one degree or another valid and relevant today.

Equality, identity, equivalence

As with many other mathematical signs and symbols, the designation of equality was originally verbal. For quite a long time, the generally accepted designation was the abbreviation ae from the Latin aequalis (“equal”). However, in the 16th century, a Welsh mathematician named Robert Record proposed two horizontal lines located one below the other as a symbol. As the scientist argued, it is impossible to think of anything more equal to each other than two parallel segments.

Despite the fact that a similar sign was used to indicate parallel lines, the new equality symbol gradually became widespread. By the way, such signs as “more” and “less”, depicting ticks turned in different directions, appeared only in the 17th-18th centuries. Today they seem intuitive to any schoolchild.

Slightly more complex signs of equivalence (two wavy lines) and identity (three horizontal parallel lines) came into use only in the second half of the 19th century.

Sign of the unknown - “X”

The history of the emergence of mathematical signs and symbols also contains very interesting cases of rethinking graphics as science develops. The sign for the unknown, today called “X,” originates in the Middle East at the dawn of the last millennium.

Back in the 10th century in the Arab world, famous at that historical period for its scientists, the concept of the unknown was denoted by a word literally translated as “something” and beginning with the sound “Ш”. In order to save materials and time, the word in treatises began to be shortened to the first letter.

Many decades later, the written works of Arab scientists ended up in the cities of the Iberian Peninsula, in the territory of modern Spain. Scientific treatises began to be translated into the national language, but a difficulty arose - in Spanish there is no phoneme “Ш”. Borrowed Arabic words starting with it were written according to a special rule and were preceded by the letter X. The scientific language of that time was Latin, in which the corresponding sign is called “X”.

Thus, the sign, which at first glance is just a randomly chosen symbol, has a deep history and was originally an abbreviation of the Arabic word for “something.”

Designation of other unknowns

Unlike “X,” Y and Z, familiar to us from school, as well as a, b, c, have a much more prosaic origin story.

In the 17th century, Descartes published a book called Geometry. In this book, the author proposed standardizing symbols in equations: in accordance with his idea, the last three letters of the Latin alphabet (starting from “X”) began to denote unknown values, and the first three - known values.

Trigonometric terms

The history of such a word as “sine” is truly unusual.

The corresponding trigonometric functions were originally named in India. The word corresponding to the concept of sine literally meant “string”. During the heyday of Arabic science, Indian treatises were translated, and the concept, which had no analogue in the Arabic language, was transcribed. By coincidence, what came out in the letter resembled the real-life word “hollow”, the semantics of which had nothing to do with the original term. As a result, when Arabic texts were translated into Latin in the 12th century, the word "sine" emerged, meaning "hollow" and established as a new mathematical concept.

But the mathematical signs and symbols for tangent and cotangent have not yet been standardized - in some countries they are usually written as tg, and in others - as tan.

Some other signs

As can be seen from the examples described above, the emergence of mathematical signs and symbols largely occurred in the 16th-17th centuries. The same period saw the emergence of today's familiar forms of recording such concepts as percentage, square root, degree.

Percentage, i.e. one hundredth, has long been designated as cto (short for Latin cento). It is believed that the sign that is generally accepted today appeared as a result of a typo about four hundred years ago. The resulting image was perceived as a successful way to shorten it and caught on.

The root sign was originally a stylized letter R (short for the Latin word radix, “root”). The upper bar, under which the expression is written today, served as parentheses and was a separate symbol, separate from the root. Parentheses were invented later - they came into widespread use thanks to the work of Leibniz (1646-1716). Thanks to his work, the integral symbol was introduced into science, looking like an elongated letter S - short for the word “sum”.

Finally, the sign for the operation of exponentiation was invented by Descartes and modified by Newton in the second half of the 17th century.

Later designations

Considering that the familiar graphic images of “plus” and “minus” were introduced into circulation only a few centuries ago, it does not seem surprising that mathematical signs and symbols denoting complex phenomena began to be used only in the century before last.

Thus, the factorial, which looks like an exclamation mark after a number or variable, appeared only in early XIX century. Around the same time, the capital “P” to denote work and the limit symbol appeared.

It is somewhat strange that the signs for Pi and the algebraic sum appeared only in the 18th century - later than, for example, the integral symbol, although intuitively it seems that they are more commonly used. The graphical representation of the ratio of circumference to diameter comes from the first letter of the Greek words meaning "circumference" and "perimeter". And the “sigma” sign for an algebraic sum was proposed by Euler in the last quarter of the 18th century.

Names of symbols in different languages

As you know, the language of science in Europe for many centuries was Latin. Physical, medical and many other terms were often borrowed in the form of transcriptions, much less often - in the form of tracing paper. Thus, many mathematical signs and symbols in English are called almost the same as in Russian, French or German. The more complex the essence of a phenomenon, the higher the likelihood that it will have the same name in different languages.

Computer notation of mathematical symbols

The simplest mathematical signs and symbols in Word are indicated by the usual key combination Shift+number from 0 to 9 in the Russian or English layout. Separate keys are reserved for some commonly used signs: plus, minus, equal, slash.

If you want to use graphic images of an integral, an algebraic sum or product, Pi, etc., you need to open the “Insert” tab in Word and find one of two buttons: “Formula” or “Symbol”. In the first case, a constructor will open, allowing you to build an entire formula within one field, and in the second, a table of symbols will open, where you can find any mathematical symbols.

How to Remember Math Symbols

Unlike chemistry and physics, where the number of symbols to remember can exceed a hundred units, mathematics operates with a relatively small number of symbols. We learn the simplest of them in early childhood, learning to add and subtract, and only at the university in certain specialties do we become familiar with a few complex mathematical signs and symbols. Pictures for children help in a matter of weeks to achieve instant recognition of the graphic image of the required operation; much more time may be needed to master the skill of performing these operations and understanding their essence.

Thus, the process of memorizing signs occurs automatically and does not require much effort.

Finally

The value of mathematical signs and symbols lies in the fact that they are easily understood by people who speak different languages ​​and are native speakers of different cultures. For this reason, it is extremely useful to understand and be able to reproduce graphical representations of various phenomena and operations.

The high level of standardization of these signs determines their use in a wide variety of fields: in the field of finance, information technology, engineering, etc. For anyone who wants to do business related to numbers and calculations, knowledge of mathematical signs and symbols and their meanings becomes a vital necessity .

Infinity.J. Wallis (1655).

First found in the treatise of the English mathematician John Valis "On Conic Sections".

The base of natural logarithms. L. Euler (1736).

Mathematical constant, transcendental number. This number is sometimes called non-feathered in honor of the Scottish scientist Napier, author of the work “Description of the Amazing Table of Logarithms” (1614). The constant first appears tacitly in an appendix to the English translation of Napier's above-mentioned work, published in 1618. The constant itself was first calculated by the Swiss mathematician Jacob Bernoulli while solving the problem of the limiting value of interest income.

2,71828182845904523...

The first known use of this constant, where it was denoted by the letter b, found in Leibniz's letters to Huygens, 1690-1691. Letter e Euler began using it in 1727, and the first publication with this letter was his work “Mechanics, or the Science of Motion, Explained Analytically” in 1736. Respectively, e usually called Euler number. Why was the letter chosen? e, exactly unknown. Perhaps this is due to the fact that the word begins with it exponential(“indicative”, “exponential”). Another assumption is that the letters a, b, c And d have already been used quite widely for other purposes, and e was the first "free" letter.

The ratio of the circumference to the diameter. W. Jones (1706), L. Euler (1736).

Mathematical constant, irrational number. The number "pi", the old name is Ludolph's number. Like any irrational number, π is represented as an infinite non-periodic decimal fraction:

π =3.141592653589793...

For the first time, the designation of this number by the Greek letter π was used by the British mathematician William Jones in the book “A New Introduction to Mathematics”, and it became generally accepted after the work of Leonhard Euler. This designation comes from the initial letter of the Greek words περιφερεια - circle, periphery and περιμετρος - perimeter. Johann Heinrich Lambert proved the irrationality of π in 1761, and Adrienne Marie Legendre proved the irrationality of π 2 in 1774. Legendre and Euler assumed that π could be transcendental, i.e. cannot satisfy any algebraic equation with integer coefficients, which was eventually proven in 1882 by Ferdinand von Lindemann.

Imaginary unit. L. Euler (1777, in print - 1794).

It is known that the equation x 2 =1 has two roots: 1 And -1 . The imaginary unit is one of the two roots of the equation x 2 = -1, denoted by a Latin letter i, another root: -i. This designation was proposed by Leonhard Euler, who took the first letter of the Latin word for this purpose imaginarius(imaginary). He also extended all standard functions to the complex domain, i.e. set of numbers representable as a+ib, Where a And b- real numbers. The term "complex number" was introduced into widespread use by the German mathematician Carl Gauss in 1831, although the term had previously been used in the same sense by the French mathematician Lazare Carnot in 1803.

Unit vectors. W. Hamilton (1853).

Unit vectors are often associated with the coordinate axes of a coordinate system (in particular, the axes of a Cartesian coordinate system). Unit vector directed along the axis X, denoted i, unit vector directed along the axis Y, denoted j, and the unit vector directed along the axis Z, denoted k. Vectors i, j, k are called unit vectors, they have unit modules. The term "ort" was introduced by the English mathematician and engineer Oliver Heaviside (1892), and the notation i, j, k- Irish mathematician William Hamilton.

Integer part of the number, antie. K.Gauss (1808).

The integer part of the number [x] of the number x is the largest integer not exceeding x. So, =5, [-3,6]=-4. The function [x] is also called "antier of x". The whole-part function symbol was introduced by Carl Gauss in 1808. Some mathematicians prefer to use instead the notation E(x), proposed in 1798 by Legendre.

Angle of parallelism. N.I. Lobachevsky (1835).

On the Lobachevsky plane - the angle between the straight lineb, passing through the pointABOUTparallel to the linea, not containing a pointABOUT, and perpendicular fromABOUT on a. α - the length of this perpendicular. As the point moves awayABOUT from the straight line athe angle of parallelism decreases from 90° to 0°. Lobachevsky gave a formula for the angle of parallelismP( α )=2arctg e - α /q , Where q— some constant associated with the curvature of Lobachevsky space.

Unknown or variable quantities. R. Descartes (1637).

In mathematics, a variable is a quantity characterized by the set of values ​​it can take. This may mean both a real physical quantity, temporarily considered in isolation from its physical context, and some abstract quantity that has no analogues in the real world. The concept of a variable arose in the 17th century. initially under the influence of the demands of natural science, which brought to the fore the study of movement, processes, and not just states. This concept required new forms for its expression. Such new forms were the letter algebra and analytical geometry of Rene Descartes. For the first time, the rectangular coordinate system and the notation x, y were introduced by Rene Descartes in his work “Discourse on Method” in 1637. Pierre Fermat also contributed to the development of the coordinate method, but his works were first published after his death. Descartes and Fermat used the coordinate method only on the plane. The coordinate method for three-dimensional space was first used by Leonhard Euler already in the 18th century.

Vector. O. Cauchy (1853).

From the very beginning, a vector is understood as an object that has a magnitude, a direction and (optionally) a point of application. The beginnings of vector calculus appeared along with the geometric model of complex numbers in Gauss (1831). Hamilton published developed operations with vectors as part of his quaternion calculus (the vector was formed by the imaginary components of the quaternion). Hamilton proposed the term vector(from the Latin word vector, carrier) and described some operations of vector analysis. Maxwell used this formalism in his works on electromagnetism, thereby drawing the attention of scientists to the new calculus. Soon Gibbs's Elements of Vector Analysis came out (1880s), and then Heaviside (1903) gave vector analysis its modern look. The vector sign itself was introduced into use by the French mathematician Augustin Louis Cauchy in 1853.

Addition, subtraction. J. Widman (1489).

The plus and minus signs were apparently invented in the German mathematical school of “Kossists” (that is, algebraists). They are used in Jan (Johannes) Widmann's textbook A Quick and Pleasant Account for All Merchants, published in 1489. Previously, addition was denoted by the letter p(from Latin plus"more") or Latin word et(conjunction “and”), and subtraction - letter m(from Latin minus"less, less") For Widmann, the plus symbol replaces not only addition, but also the conjunction “and.” The origin of these symbols is unclear, but most likely they were previously used in trading as indicators of profit and loss. Both symbols soon became common in Europe - with the exception of Italy, which continued to use the old designations for about a century.

Multiplication. W. Outred (1631), G. Leibniz (1698).

The multiplication sign in the form of an oblique cross was introduced in 1631 by the Englishman William Oughtred. Before him, the letter was most often used M, although other notations were also proposed: the rectangle symbol (French mathematician Erigon, 1634), asterisk (Swiss mathematician Johann Rahn, 1659). Later, Gottfried Wilhelm Leibniz replaced the cross with a dot (late 17th century) so as not to confuse it with the letter x; before him, such symbolism was found among the German astronomer and mathematician Regiomontanus (15th century) and the English scientist Thomas Herriot (1560 -1621).

Division. I.Ran (1659), G.Leibniz (1684).

William Oughtred used a slash / as a division sign. Gottfried Leibniz began to denote division with a colon. Before them, the letter was also often used D. Starting with Fibonacci, the horizontal line of the fraction is also used, which was used by Heron, Diophantus and in Arabic works. In England and the USA, the symbol ÷ (obelus), which was proposed by Johann Rahn (possibly with the participation of John Pell) in 1659, became widespread. An attempt by the American National Committee on Mathematical Standards ( National Committee on Mathematical Requirements) to remove obelus from practice (1923) was unsuccessful.

Percent. M. de la Porte (1685).

A hundredth of a whole, taken as a unit. The word “percent” itself comes from the Latin “pro centum”, which means “per hundred”. In 1685, the book “Manual of Commercial Arithmetic” by Mathieu de la Porte was published in Paris. In one place they talked about percentages, which were then designated “cto” (short for cento). However, the typesetter mistook this "cto" for a fraction and printed "%". So, due to a typo, this sign came into use.

Degrees. R. Descartes (1637), I. Newton (1676).

The modern notation for the exponent was introduced by Rene Descartes in his “ Geometry"(1637), however, only for natural powers with exponents greater than 2. Later, Isaac Newton extended this form of notation to negative and fractional exponents (1676), the interpretation of which had already been proposed by this time: the Flemish mathematician and engineer Simon Stevin, the English mathematician John Wallis and French mathematician Albert Girard.

Arithmetic root n-th power of a real number A≥0, - non-negative number n-th degree of which is equal to A. The arithmetic root of the 2nd degree is called a square root and can be written without indicating the degree: √. An arithmetic root of the 3rd degree is called a cube root. Medieval mathematicians (for example, Cardano) denoted the square root with the symbol R x (from the Latin Radix, root). The modern notation was first used by the German mathematician Christoph Rudolf, from the Cossist school, in 1525. This symbol comes from the stylized first letter of the same word radix. At first there was no line above the radical expression; it was later introduced by Descartes (1637) for a different purpose (instead of parentheses), and this feature soon merged with the root sign. In the 16th century, the cube root was denoted as follows: R x .u.cu (from lat. Radix universalis cubica). Albert Girard (1629) began to use the familiar notation for a root of an arbitrary degree. This format was established thanks to Isaac Newton and Gottfried Leibniz.

Logarithm, decimal logarithm, natural logarithm. I. Kepler (1624), B. Cavalieri (1632), A. Prinsheim (1893).

The term "logarithm" belongs to the Scottish mathematician John Napier ( “Description of the amazing table of logarithms”, 1614); it arose from a combination of the Greek words λογος (word, relation) and αριθμος (number). J. Napier's logarithm is an auxiliary number for measuring the ratio of two numbers. Modern definition The logarithm was first given by the English mathematician William Gardiner (1742). By definition, the logarithm of a number b based on a (a ≠ 1, a > 0) - exponent m, to which the number should be raised a(called the logarithm base) to get b. Designated log a b. So, m = log a b, If a m = b.

The first tables of decimal logarithms were published in 1617 by Oxford mathematics professor Henry Briggs. Therefore, abroad, decimal logarithms are often called Briggs logarithms. The term “natural logarithm” was introduced by Pietro Mengoli (1659) and Nicholas Mercator (1668), although the London mathematics teacher John Spidell compiled a table of natural logarithms back in 1619.

Before late XIX century there was no generally accepted notation for the logarithm, the base a indicated to the left and above the symbol log, then above it. Ultimately, mathematicians came to the conclusion that the most convenient place for the base is below the line, after the symbol log. The logarithm sign - the result of the abbreviation of the word "logarithm" - appears in various forms almost simultaneously with the appearance of the first tables of logarithms, e.g. Log- by I. Kepler (1624) and G. Briggs (1631), log- by B. Cavalieri (1632). Designation ln For natural logarithm introduced by the German mathematician Alfred Pringsheim (1893).

Sine, cosine, tangent, cotangent. W. Outred (mid-17th century), I. Bernoulli (18th century), L. Euler (1748, 1753).

The abbreviations for sine and cosine were introduced by William Oughtred in the mid-17th century. Abbreviations for tangent and cotangent: tg, ctg introduced by Johann Bernoulli in the 18th century, they became widespread in Germany and Russia. In other countries the names of these functions are used tan, cot proposed by Albert Girard even earlier, in early XVII century. Leonhard Euler (1748, 1753) brought the theory of trigonometric functions into its modern form, and we owe it to him for the consolidation of real symbolism.The term "trigonometric functions" was introduced by the German mathematician and physicist Georg Simon Klügel in 1770.

Indian mathematicians originally called the sine line "arha-jiva"(“half-string”, that is, half a chord), then the word "archa" was discarded and the sine line began to be called simply "jiva". Arabic translators did not translate the word "jiva" Arabic word "vatar", denoting string and chord, and transcribed in Arabic letters and began to call the sine line "jiba". Since in Arabic short vowels are not marked, but long “i” in the word "jiba" denoted in the same way as the semivowel “th”, the Arabs began to pronounce the name of the sine line "jibe", which literally means “hollow”, “sinus”. When translating Arabic works into Latin, European translators translated the word "jibe" Latin word sinus, having the same meaning.The term "tangent" (from lat.tangents- touching) was introduced by the Danish mathematician Thomas Fincke in his book The Geometry of the Round (1583).

Arcsine. K. Scherfer (1772), J. Lagrange (1772).

Inverse trigonometric functions are mathematical functions that are the inverse of trigonometric functions. The name of the inverse trigonometric function is formed from the name of the corresponding trigonometric function by adding the prefix "arc" (from Lat. arc- arc).The inverse trigonometric functions usually include six functions: arcsine (arcsin), arccosine (arccos), arctangent (arctg), arccotangent (arcctg), arcsecant (arcsec) and arccosecant (arccosec). Special symbols for inverse trigonometric functions were first used by Daniel Bernoulli (1729, 1736).Manner of denoting inverse trigonometric functions using a prefix arc(from lat. arcus, arc) appeared with the Austrian mathematician Karl Scherfer and was consolidated thanks to the French mathematician, astronomer and mechanic Joseph Louis Lagrange. It was meant that, for example, an ordinary sine allows one to find a chord subtending it along an arc of a circle, and the inverse function solves the opposite problem. Until the end of the 19th century, the English and German mathematical schools proposed other notations: sin -1 and 1/sin, but they are not widely used.

Hyperbolic sine, hyperbolic cosine. V. Riccati (1757).

Historians discovered the first appearance of hyperbolic functions in the works of the English mathematician Abraham de Moivre (1707, 1722). A modern definition and a detailed study of them was carried out by the Italian Vincenzo Riccati in 1757 in his work “Opusculorum”, he also proposed their designations: sh,ch. Riccati started from considering the unit hyperbola. An independent discovery and further study of the properties of hyperbolic functions was carried out by the German mathematician, physicist and philosopher Johann Lambert (1768), who established the wide parallelism of the formulas of ordinary and hyperbolic trigonometry. N.I. Lobachevsky subsequently used this parallelism in an attempt to prove the consistency of non-Euclidean geometry, in which ordinary trigonometry is replaced by hyperbolic one.

Just as the trigonometric sine and cosine are the coordinates of a point on the coordinate circle, the hyperbolic sine and cosine are the coordinates of a point on a hyperbola. Hyperbolic functions are expressed through an exponential and are closely related to trigonometric functions: sh(x)=0.5(e x -e -x) , ch(x)=0.5(e x +e -x). By analogy with trigonometric functions, hyperbolic tangent and cotangent are defined as the ratios of hyperbolic sine and cosine, cosine and sine, respectively.

Differential. G. Leibniz (1675, published 1684).

The main, linear part of the function increment.If the function y=f(x) one variable x has at x=x 0derivative, and incrementΔy=f(x 0 +?x)-f(x 0)functions f(x) can be represented in the formΔy=f"(x 0 )Δx+R(Δx) , where is the member R infinitesimal compared toΔx. First memberdy=f"(x 0 )Δxin this expansion and is called the differential of the function f(x) at the pointx 0. IN works of Gottfried Leibniz, Jacob and Johann Bernoulli the word"differentia"was used in the sense of “increment”, it was denoted by I. Bernoulli through Δ. G. Leibniz (1675, published 1684) used the notation for the “infinitesimal difference”d- the first letter of the word"differential", formed by him from"differentia".

Indefinite integral. G. Leibniz (1675, published 1686).

The word "integral" was first used in print by Jacob Bernoulli (1690). Perhaps the term is derived from the Latin integer- whole. According to another assumption, the basis was the Latin word integro- bring to its previous state, restore. The sign ∫ is used to represent an integral in mathematics and is a stylized representation of the first letter of the Latin word summa - sum. It was first used by the German mathematician and founder of differential and integral calculus, Gottfried Leibniz in late XVII century. Another of the founders of differential and integral calculus, Isaac Newton, did not propose an alternative symbolism for the integral in his works, although he tried various options: a vertical bar above a function, or a square symbol that precedes or borders a function. Indefinite integral for a function y=f(x) is the set of all antiderivatives of a given function.

Definite integral. J. Fourier (1819-1822).

Definite integral of a function f(x) with a lower limit a and upper limit b can be defined as the difference F(b) - F(a) = a ∫ b f(x)dx , Where F(x)- some antiderivative of a function f(x) . Definite integral a ∫ b f(x)dx numerically equal to the area of ​​the figure bounded by the x-axis and straight lines x=a And x=b and the graph of the function f(x). The design of a definite integral in the form we are familiar with was proposed by the French mathematician and physicist Jean Baptiste Joseph Fourier at the beginning of the 19th century.

Derivative. G. Leibniz (1675), J. Lagrange (1770, 1779).

Derivative is the basic concept of differential calculus, characterizing the rate of change of a function f(x) when the argument changes x . It is defined as the limit of the ratio of the increment of a function to the increment of its argument as the increment of the argument tends to zero, if such a limit exists. A function that has a finite derivative at some point is called differentiable at that point. The process of calculating the derivative is called differentiation. The reverse process is integration. In classical differential calculus, the derivative is most often defined through the concepts of the theory of limits, but historically the theory of limits appeared later than differential calculus.

The term “derivative” was introduced by Joseph Louis Lagrange in 1797, the denotation of a derivative using a stroke is also used by him (1770, 1779), and dy/dx- Gottfried Leibniz in 1675. The manner of denoting the time derivative with a dot over a letter comes from Newton (1691).The Russian term “derivative of a function” was first used by a Russian mathematicianVasily Ivanovich Viskovatov (1779-1812).

Partial derivative. A. Legendre (1786), J. Lagrange (1797, 1801).

For functions of many variables, partial derivatives are defined - derivatives with respect to one of the arguments, calculated under the assumption that the remaining arguments are constant. Designations ∂f/ ∂ x, ∂ z/ ∂ y introduced by French mathematician Adrien Marie Legendre in 1786; fx",z x "- Joseph Louis Lagrange (1797, 1801); ∂ 2 z/ ∂ x 2, ∂ 2 z/ ∂ x ∂ y- partial derivatives of the second order - German mathematician Carl Gustav Jacob Jacobi (1837).

Difference, increment. I. Bernoulli (late 17th century - first half of the 18th century), L. Euler (1755).

The designation of increment by the letter Δ was first used by the Swiss mathematician Johann Bernoulli. IN general practice The use of the delta symbol came into use after the work of Leonhard Euler in 1755.

Sum. L. Euler (1755).

Sum is the result of adding quantities (numbers, functions, vectors, matrices, etc.). To denote the sum of n numbers a 1, a 2, ..., a n, the Greek letter “sigma” Σ is used: a 1 + a 2 + ... + a n = Σ n i=1 a i = Σ n 1 a i. The Σ sign for the sum was introduced by Leonhard Euler in 1755.

Work. K.Gauss (1812).

A product is the result of multiplication. To denote the product of n numbers a 1, a 2, ..., a n, the Greek letter pi Π is used: a 1 · a 2 · ... · a n = Π n i=1 a i = Π n 1 a i. For example, 1 · 3 · 5 · ... · 97 · 99 = ? 50 1 (2i-1). The Π sign for a product was introduced by the German mathematician Carl Gauss in 1812. In Russian mathematical literature, the term “product” was first encountered by Leonty Filippovich Magnitsky in 1703.

Factorial. K. Crump (1808).

The factorial of a number n (denoted n!, pronounced "en factorial") is the product of all natural numbers up to n inclusive: n! = 1·2·3·...·n. For example, 5! = 1·2·3·4·5 = 120. By definition, 0 is assumed! = 1. Factorial is defined only for non-negative integers. The factorial of n is equal to the number of permutations of n elements. For example, 3! = 6, indeed,

♣ ♦

♣ ♦

♣ ♦

♦ ♣

♦ ♣

♦ ♣

All six and only six permutations of three elements.

The term "factorial" was introduced by the French mathematician and politician Louis Francois Antoine Arbogast (1800), the designation n! - French mathematician Christian Crump (1808).

Modulus, absolute value. K. Weierstrass (1841).

The absolute value of a real number x is a non-negative number defined as follows: |x| = x for x ≥ 0, and |x| = -x for x ≤ 0. For example, |7| = 7, |- 0.23| = -(-0.23) = 0.23. The modulus of a complex number z = a + ib is a real number equal to √(a 2 + b 2).

It is believed that the term “module” was proposed by the English mathematician and philosopher, Newton’s student, Roger Cotes. Gottfried Leibniz also used this function, which he called “modulus” and denoted: mol x. The generally accepted notation for absolute magnitude was introduced in 1841 by the German mathematician Karl Weierstrass. For complex numbers, this concept was introduced by French mathematicians Augustin Cauchy and Jean Robert Argan at the beginning of the 19th century. In 1903, the Austrian scientist Konrad Lorenz used the same symbolism for the length of a vector.

Norm. E. Schmidt (1908).

A norm is a functional defined on a vector space and generalizing the concept of the length of a vector or modulus of a number. The "norm" sign (from the Latin word "norma" - "rule", "pattern") was introduced by the German mathematician Erhard Schmidt in 1908.

Limit. S. Lhuillier (1786), W. Hamilton (1853), many mathematicians (until the beginning of the twentieth century)

Limit is one of the basic concepts of mathematical analysis, meaning that a certain variable value in the process of its change under consideration indefinitely approaches a certain constant value. The concept of a limit was used intuitively in the second half of the 17th century by Isaac Newton, as well as by 18th-century mathematicians such as Leonhard Euler and Joseph Louis Lagrange. The first rigorous definitions of the sequence limit were given by Bernard Bolzano in 1816 and Augustin Cauchy in 1821. The symbol lim (the first 3 letters from the Latin word limes - border) appeared in 1787 by the Swiss mathematician Simon Antoine Jean Lhuillier, but its use did not yet resemble modern ones. The expression lim in a more familiar form was first used by the Irish mathematician William Hamilton in 1853.Weierstrass introduced a designation close to the modern one, but instead of the familiar arrow, he used an equal sign. The arrow appeared at the beginning of the 20th century among several mathematicians at once - for example, the English mathematician Godfried Hardy in 1908.

Zeta function, d Riemann zeta function. B. Riemann (1857).

Analytical function of a complex variable s = σ + it, for σ > 1, determined absolutely and uniformly by a convergent Dirichlet series:

ζ(s) = 1 -s + 2 -s + 3 -s + ... .

For σ > 1, the representation in the form of the Euler product is valid:

ζ(s) = Π p (1-p -s) -s,

where the product is taken over all prime p. The zeta function plays a big role in number theory.As a function of a real variable, the zeta function was introduced in 1737 (published in 1744) by L. Euler, who indicated its expansion into a product. Then this function was considered by the German mathematician L. Dirichlet and, especially successfully, Russian mathematician and mechanic P.L. Chebyshev when studying the distribution law prime numbers. However, the most profound properties of the zeta function were discovered later, after the work of the German mathematician Georg Friedrich Bernhard Riemann (1859), where the zeta function was considered as a function of a complex variable; He also introduced the name “zeta function” and the designation ζ(s) in 1857.

Gamma function, Euler Γ function. A. Legendre (1814).

The Gamma function is a mathematical function that extends the concept of factorial to the field of complex numbers. Usually denoted by Γ(z). The G-function was first introduced by Leonhard Euler in 1729; it is determined by the formula:

Γ(z) = limn→∞ n!·n z /z(z+1)...(z+n).

A large number of integrals, infinite products and sums of series are expressed through the G-function. Widely used in analytical number theory. The name "Gamma function" and the notation Γ(z) were proposed by the French mathematician Adrien Marie Legendre in 1814.

Beta function, B function, Euler B function. J. Binet (1839).

A function of two variables p and q, defined for p>0, q>0 by the equality:

B(p, q) = 0 ∫ 1 x p-1 (1-x) q-1 dx.

The beta function can be expressed through the Γ-function: B(p, q) = Γ(p)Г(q)/Г(p+q).Just as the gamma function for integers is a generalization of factorial, the beta function is, in a sense, a generalization of binomial coefficients.

The beta function describes many propertieselementary particles participating in strong interaction. This feature was noticed by the Italian theoretical physicistGabriele Veneziano in 1968. This marked the beginning string theory.

The name “beta function” and the designation B(p, q) were introduced in 1839 by the French mathematician, mechanic and astronomer Jacques Philippe Marie Binet.

Laplace operator, Laplacian. R. Murphy (1833).

Linear differential operator Δ, which assigns functions φ(x 1, x 2, ..., x n) of n variables x 1, x 2, ..., x n:

Δφ = ∂ 2 φ/∂х 1 2 + ∂ 2 φ/∂х 2 2 + ... + ∂ 2 φ/∂х n 2.

In particular, for a function φ(x) of one variable, the Laplace operator coincides with the operator of the 2nd derivative: Δφ = d 2 φ/dx 2 . The equation Δφ = 0 is usually called Laplace's equation; This is where the names “Laplace operator” or “Laplacian” come from. The designation Δ was introduced by the English physicist and mathematician Robert Murphy in 1833.

Hamilton operator, nabla operator, Hamiltonian. O. Heaviside (1892).

Vector differential operator of the form

∇ = ∂/∂x i+ ∂/∂y · j+ ∂/∂z · k,

Where i, j, And k- coordinate unit vectors. The basic operations of vector analysis, as well as the Laplace operator, are expressed in a natural way through the Nabla operator.

In 1853, Irish mathematician William Rowan Hamilton introduced this operator and coined the symbol ∇ for it as an inverted Greek letter Δ (delta). In Hamilton, the tip of the symbol pointed to the left; later, in the works of the Scottish mathematician and physicist Peter Guthrie Tate, the symbol acquired its modern form. Hamilton called this symbol "atled" (the word "delta" read backwards). Later, English scholars, including Oliver Heaviside, began to call this symbol "nabla", after the name of the letter ∇ in the Phoenician alphabet, where it occurs. The origin of the letter is associated with musical instrument type of harp, ναβλα (nabla) means "harp" in ancient Greek. The operator was called the Hamilton operator, or nabla operator.

Function. I. Bernoulli (1718), L. Euler (1734).

A mathematical concept that reflects the relationship between elements of sets. We can say that a function is a “law”, a “rule” according to which each element of one set (called the domain of definition) is associated with some element of another set (called the domain of values). The mathematical concept of a function expresses the intuitive idea of ​​how one quantity completely determines the value of another quantity. Often the term "function" refers to a numerical function; that is, a function that puts some numbers in correspondence with others. For a long time mathematicians specified arguments without parentheses, for example, like this - φх. This notation was first used by the Swiss mathematician Johann Bernoulli in 1718.Parentheses were used only in the case of multiple arguments or if the argument was a complex expression. Echoes of those times are the recordings still in use todaysin x, log xetc. But gradually the use of parentheses, f(x) , became a general rule. And the main credit for this belongs to Leonhard Euler.

Equality. R. Record (1557).

The equals sign was proposed by the Welsh physician and mathematician Robert Record in 1557; the outline of the symbol was much longer than the current one, as it imitated the image of two parallel segments. The author explained that there is nothing more equal in the world than two parallel segments of the same length. Before this, in ancient and medieval mathematics equality was denoted verbally (for example est egale). In the 17th century, Rene Descartes began to use æ (from lat. aequalis), A modern sign he used equalities to indicate that the coefficient could be negative. François Viète used the equal sign to denote subtraction. The Record symbol did not become widespread immediately. The spread of the Record symbol was hampered by the fact that since ancient times the same symbol was used to indicate the parallelism of straight lines; In the end, it was decided to make the parallelism symbol vertical. In continental Europe, the "=" sign was introduced by Gottfried Leibniz only at the turn of the 17th-18th centuries, that is, more than 100 years after the death of Robert Record, who first used it for this purpose.

Approximately equal, approximately equal. A.Gunther (1882).

Sign " ≈ " was introduced into use as a symbol for the relation "approximately equal" by the German mathematician and physicist Adam Wilhelm Sigmund Günther in 1882.

More less. T. Harriot (1631).

These two signs were introduced into use by the English astronomer, mathematician, ethnographer and translator Thomas Harriot in 1631; before that, the words “more” and “less” were used.

Comparability. K.Gauss (1801).

Comparison is a relationship between two integers n and m, meaning that the difference n-m of these numbers is divided by a given integer a, called the comparison modulus; it is written: n≡m(mod а) and reads “the numbers n and m are comparable modulo a”. For example, 3≡11(mod 4), since 3-11 is divisible by 4; the numbers 3 and 11 are comparable modulo 4. Congruences have many properties similar to those of equalities. Thus, a term located in one part of the comparison can be transferred with the opposite sign to another part, and comparisons with the same module can be added, subtracted, multiplied, both parts of the comparison can be multiplied by the same number, etc. For example,

3≡9+2(mod 4) and 3-2≡9(mod 4)

At the same time true comparisons. And from a pair of correct comparisons 3≡11(mod 4) and 1≡5(mod 4) the following follows:

3+1≡11+5(mod 4)

3-1≡11-5(mod 4)

3·1≡11·5(mod 4)

3 2 ≡11 2 (mod 4)

3·23≡11·23(mod 4)

Number theory deals with methods for solving various comparisons, i.e. methods for finding integers that satisfy comparisons of one type or another. Modulo comparisons were first used by the German mathematician Carl Gauss in his 1801 book Arithmetic Studies. He also proposed symbolism for comparisons that was established in mathematics.

Identity. B. Riemann (1857).

Identity is the equality of two analytical expressions, valid for any permissible values ​​of the letters included in it. The equality a+b = b+a is valid for all numerical values a and b, and therefore is an identity. To record identities, in some cases, since 1857, the sign “≡” (read “identically equal”) has been used, the author of which in this use is the German mathematician Georg Friedrich Bernhard Riemann. You can write down a+b ≡ b+a.

Perpendicularity. P. Erigon (1634).

Perpendicularity is the relative position of two straight lines, planes, or a straight line and a plane, in which the indicated figures form a right angle. The sign ⊥ to denote perpendicularity was introduced in 1634 by the French mathematician and astronomer Pierre Erigon. The concept of perpendicularity has a number of generalizations, but all of them, as a rule, are accompanied by the sign ⊥.

Parallelism. W. Outred (posthumous edition 1677).

Parallelism is the relationship between certain geometric figures; for example, straight. Defined differently depending on different geometries; for example, in the geometry of Euclid and in the geometry of Lobachevsky. The sign of parallelism has been known since ancient times, it was used by Heron and Pappus of Alexandria. At first, the symbol was similar to the current equals sign (only more extended), but with the advent of the latter, to avoid confusion, the symbol was turned vertically ||. It appeared in this form for the first time in the posthumous edition of the works of the English mathematician William Oughtred in 1677.

Intersection, union. J. Peano (1888).

The intersection of sets is a set that contains those and only those elements that simultaneously belong to all given sets. A union of sets is a set that contains all the elements of the original sets. Intersection and union are also called operations on sets that assign new sets to certain ones according to the rules indicated above. Denoted by ∩ and ∪, respectively. For example, if

A= (♠ ♣ ) And B= (♣ ♦),

That

A∩B= {♣ }

A∪B= {♠ ♣ ♦ } .

Contains, contains. E. Schroeder (1890).

If A and B are two sets and there are no elements in A that do not belong to B, then they say that A is contained in B. They write A⊂B or B⊃A (B contains A). For example,

{♠}⊂{♠ ♣}⊂{♠ ♣ ♦ }

{♠ ♣ ♦ }⊃{ ♦ }⊃{♦ }

The symbols “contains” and “contains” appeared in 1890 by the German mathematician and logician Ernst Schroeder.

Affiliation. J. Peano (1895).

If a is an element of the set A, then write a∈A and read “a belongs to A.” If a is not an element of the set A, write a∉A and read “a does not belong to A.” At first, the relations “contained” and “belongs” (“is an element”) were not distinguished, but over time these concepts required differentiation. The symbol ∈ was first used by the Italian mathematician Giuseppe Peano in 1895. The symbol ∈ comes from the first letter of the Greek word εστι - to be.

Quantifier of universality, quantifier of existence. G. Gentzen (1935), C. Pierce (1885).

Quantifier - common name for logical operations indicating the domain of truth of a predicate (mathematical statement). Philosophers have long paid attention to logical operations that limit the domain of truth of a predicate, but have not identified them as a separate class of operations. Although quantifier-logical constructions are widely used in both scientific and everyday speech, their formalization occurred only in 1879, in the book of the German logician, mathematician and philosopher Friedrich Ludwig Gottlob Frege “The Calculus of Concepts”. Frege's notation looked like cumbersome graphic constructions and was not accepted. Subsequently, many more successful symbols were proposed, but the notations that became generally accepted were ∃ for the existential quantifier (read “exists”, “there is”), proposed by the American philosopher, logician and mathematician Charles Peirce in 1885, and ∀ for the universal quantifier (read “any” , "every", "everyone"), formed by the German mathematician and logician Gerhard Karl Erich Gentzen in 1935 by analogy with the symbol of the existential quantifier (inverted first letters English words Existence (existence) and Any (any)). For example, record

(∀ε>0) (∃δ>0) (∀x≠x 0 , |x-x 0 |<δ) (|f(x)-A|<ε)

reads like this: “for any ε>0 there is δ>0 such that for all x not equal to x 0 and satisfying the inequality |x-x 0 |<δ, выполняется неравенство |f(x)-A|<ε".

Empty set. N. Bourbaki (1939).

A set that does not contain a single element. The sign of the empty set was introduced in the books of Nicolas Bourbaki in 1939. Bourbaki is the collective pseudonym of a group of French mathematicians created in 1935. One of the members of the Bourbaki group was Andre Weil, the author of the Ø symbol.

Q.E.D. D. Knuth (1978).

In mathematics, proof is understood as a sequence of reasoning built on certain rules, showing that a certain statement is true. Since the Renaissance, the end of a proof has been denoted by mathematicians by the abbreviation "Q.E.D.", from the Latin expression "Quod Erat Demonstrandum" - "What was required to be proved." When creating the computer layout system ΤΕΧ in 1978, American computer science professor Donald Edwin Knuth used a symbol: a filled square, the so-called “Halmos symbol”, named after the Hungarian-born American mathematician Paul Richard Halmos. Today, the completion of a proof is usually indicated by the Halmos Symbol. As an alternative, other signs are used: an empty square, a right triangle, // (two forward slashes), as well as the Russian abbreviation “ch.t.d.”