Algebraic operation

Algebraic operations in the solution to the quadratic equation. The radical sign √, denoting a square root, is equivalent to exponentiation to the power of ⁠1/2⁠. The ± sign means the equation can be written with either a + or a – sign.

In mathematics, a basic algebraic operation is any one of the common operations of elementary algebra, which include addition, subtraction, multiplication, division, raising to a whole number power, and taking roots (fractional power). ^[1] These operations may be performed on numbers, in which case they are often called arithmetic operations . They may also be performed, in a similar way, on variables, algebraic expressions, ^[2] and more generally, on elements of algebraic structures, such as groups and fields. ^[3] An algebraic operation may also be defined more generally as a function from a Cartesian power from a given set to the same set. ^[4]

The term algebraic operation may also be used for operations that may be defined by compounding basic algebraic operations, such as the dot product. In calculus and mathematical analysis, algebraic operation is also used for the operations that may be defined by purely algebraic methods. For example, exponentiation with an integer or rational exponent is an algebraic operation, but not the general exponentiation with a real or complex exponent. Also, the derivative is an operation that is not algebraic.

Notation

Multiplication symbols are usually omitted, and implied, when there is no operator between two variables or terms, or when a coefficient is used. For example, 3 × x² is written as 3x², and 2 × x × y is written as 2xy. ^[5] Sometimes, multiplication symbols are replaced with either a dot or center-dot, so that x × y is written as either x . y or x · y. Plain text, programming languages, and calculators also use a single asterisk to represent the multiplication symbol, ^[6] and it must be explicitly used; for example, 3x is written as 3 * x.

Rather than using the ambiguous division sign (÷), ^{[lower-alpha 1]} division is usually represented with a vinculum, a horizontal line, as in ⁠3/x + 1⁠. In plain text and programming languages, a slash (also called a solidus) is used, e.g. 3 / (x + 1).

Exponents are usually formatted using superscripts, as in x². In plain text, the TeX mark-up language, and some programming languages such as MATLAB and Julia, the caret symbol, ^, represents exponents, so x² is written as x ^ 2. ^{[8] [9]} In programming languages such as Ada, ^[10] Fortran, ^[11] Perl, ^[12] Python ^[13] and Ruby, ^[14] a double asterisk is used, so x² is written as x ** 2.

The plus–minus sign, ±, is used as a shorthand notation for two expressions written as one, representing one expression with a plus sign, the other with a minus sign. For example, y = x ± 1 represents the two equations y = x + 1 and y = x − 1. Sometimes, it is used for denoting a positive-or-negative term such as ±x.

Arithmetic vs algebraic operations

Algebraic operations work in the same way as arithmetic operations, as can be seen in the table below.

Operation	Arithmetic Example	Algebra Example	Comments ≡ means "equivalent to" ≢ means "not equivalent to"
Addition	${\displaystyle (5\times 5)+5+5+3}$ equivalent to: ${\displaystyle 5^{2}+(2\times 5)+3}$	${\displaystyle (b\times b)+b+b+a}$ equivalent to: ${\displaystyle b^{2}+2b+a}$	${\displaystyle {\begin{aligned}2\times b&\equiv 2b\\b+b+b&\equiv 3b\\b\times b&\equiv b^{2}\end{aligned}}}$
Subtraction	${\displaystyle (7\times 7)-7-5}$ equivalent to: ${\displaystyle 7^{2}-7-5}$	${\displaystyle (b\times b)-b-a}$ equivalent to: ${\displaystyle b^{2}-b-a}$	${\displaystyle {\begin{aligned}b^{2}-b&\not \equiv b\\3b-b&\equiv 2b\\b^{2}-b&\equiv b(b-1)\end{aligned}}}$
Multiplication	${\displaystyle 3\times 5}$ or ${\displaystyle 3\ .\ 5}$  or  ${\displaystyle 3\cdot 5}$ or  ${\displaystyle (3)(5)}$	${\displaystyle a\times b}$ or ${\displaystyle a.b}$  or  ${\displaystyle a\cdot b}$ or  ${\displaystyle ab}$	${\displaystyle a\times a\times a}$ is the same as ${\displaystyle a^{3}}$
Division	${\displaystyle 12\div 4}$ or  ${\displaystyle 12/4}$ or  ${\displaystyle {\frac {12}{4}}}$	${\displaystyle b\div a}$ or  ${\displaystyle b/a}$ or  ${\displaystyle {\frac {b}{a}}}$	${\displaystyle {\frac {a+b}{3}}\equiv {\tfrac {1}{3}}\times (a+b)}$
Exponentiation	${\displaystyle 3^{\frac {1}{2}}}$  ${\displaystyle 2^{3}}$	${\displaystyle a^{\frac {1}{2}}}$  ${\displaystyle b^{3}}$	${\displaystyle a^{\frac {1}{2}}}$ is the same as ${\displaystyle {\sqrt {a}}}$  ${\displaystyle b^{3}}$ is the same as ${\displaystyle b\times b\times b}$

Note: the use of the letters ${\displaystyle a}$ and ${\displaystyle b}$ is arbitrary, and the examples would have been equally valid if ${\displaystyle x}$ and ${\displaystyle y}$ were used.

Properties of arithmetic and algebraic operations

Property	Arithmetic Example	Algebra Example	Comments ≡ means "equivalent to" ≢ means "not equivalent to"
Commutativity	${\displaystyle 3+5=5+3}$ ${\displaystyle 3\times 5=5\times 3}$	${\displaystyle a+b=b+a}$ ${\displaystyle a\times b=b\times a}$	Addition and multiplication are commutative and associative. [15] Subtraction and division are not: e.g. ${\displaystyle a-b\not \equiv b-a}$
Associativity	${\displaystyle (3+5)+7=3+(5+7)}$ ${\displaystyle (3\times 5)\times 7=3\times (5\times 7)}$	${\displaystyle (a+b)+c=a+(b+c)}$ ${\displaystyle (a\times b)\times c=a\times (b\times c)}$

See also

• Algebraic expression
• Algebraic function
• Elementary algebra
• Factoring a quadratic expression
• Order of operations

Notes

1. In some countries, this symbol indicates subtraction or a wrong answer. ISO 80000-2 advises that it not be used. ^[7] For more information, see Obelus.

References

1. "algebraic operation | Encyclopedia.com". www.encyclopedia.com. Retrieved 2020-08-27.
2. William Smyth, Elementary algebra: for schools and academies, Publisher Bailey and Noyes, 1864, "Algebraic Operations"
3. Horatio Nelson Robinson, New elementary algebra: containing the rudiments of science for schools and academies, Ivison, Phinney, Blakeman, & Co., 1866, page 7
4. "Algebraic operation - Encyclopedia of Mathematics". encyclopediaofmath.org. Retrieved 2020-08-27.
5. Sin Kwai Meng, Chip Wai Lung, Ng Song Beng, "Algebraic notation", in Mathematics Matters Secondary 1 Express Textbook, Publisher Panpac Education Pte Ltd, ISBN   9812738827, 9789812738820, page 68
6. William P. Berlinghoff, Fernando Q. Gouvêa, Math through the Ages: A Gentle History for Teachers and Others, Publisher MAA, 2004, ISBN   0883857367, 9780883857366, page 75
7. ISO 80000-2, Section 9 "Operations", 2-9.6
8. Ramesh Bangia, Dictionary of Information Technology, Publisher Laxmi Publications, Ltd., 2010, ISBN   9380298153, 9789380298153, page 212
9. George Grätzer, First Steps in LaTeX, Publisher Springer, 1999, ISBN   0817641327, 9780817641320, page 17
10. S. Tucker Taft, Robert A. Duff, Randall L. Brukardt, Erhard Ploedereder, Pascal Leroy, Ada 2005 Reference Manual, Volume 4348 of Lecture Notes in Computer Science, Publisher Springer, 2007, ISBN   3540693351, 9783540693352, page 13
11. C. Xavier, Fortran 77 And Numerical Methods, Publisher New Age International, 1994, ISBN   812240670X, 9788122406702, page 20
12. Randal Schwartz, brian foy, Tom Phoenix, Learning Perl, Publisher O'Reilly Media, Inc., 2011, ISBN   1449313140, 9781449313142, page 24
13. Matthew A. Telles, Python Power!: The Comprehensive Guide, Publisher Course Technology PTR, 2008, ISBN   1598631586, 9781598631586, page 46
14. Kevin C. Baird, Ruby by Example: Concepts and Code, Publisher No Starch Press, 2007, ISBN   1593271484, 9781593271480, page 72
15. Ron Larson, Robert Hostetler, Bruce H. Edwards, Algebra And Trigonometry: A Graphing Approach, Publisher: Cengage Learning, 2007, ISBN   061885195X, 9780618851959, 1114 pages, page 7