# Notation

Math syntax and notation. This page is intended to show how math concepts, operators, and symbols are used. Alternative notation styles are talked about and disambiguated.

## Arithmetic

In mathematics the plus symbol represents addition between two numbers. Addition is the process of combining two things together.

Subtraction

In mathematics the minus symbol represents the subtraction operator. The expression on the right is subtracted from the expression on the left.

Multiplication

A dot between two numbers denotes multiplication in mathematics.

Multiplication Parentheses

Two expressions placed next to eachother and separated by parenthesis are assumed to be multiplied together.

Multiplication Variables

In mathematics when two variables are next to each other the implied operation is multiplication. This makes many equations and formulas more simple.

Division

In mathematics there are multiple different ways to represent division. The obelus is often used in elementary mathematics, then later the horizontal bar is adopted for convenience, and the forward slash is used because of the prevelence of computers and calculators.

Fraction

A fraction is represented using a horizontal bar between two expressions. The expression on top is called the numerator and the expression on bottom is called the denominator.

Grouping

In mathematics parentheses are used to group expressions to be evaluated together and organize the order of operations. Everything within the parantheses is evaluated, then the rest of the calculation is carried out.

Decimal Point

The decimal point is used to separate the whole part of a number from the decimal part. The whole part is represented using number digits to the left of the decimal point. The decimal part is also represented using digits to the right of the decimal point.

Ratio

The syntax for a ratio is two numbers separated by the colon symbol.

## Algebra

Variable

A variable is a letter or symbol that represents a value that either changes or is unknown.

Function

In mathematics f(x) represents the notation of a function that takes in a number x and returns a number as output.

Slope

Slope is denoted as the change in y over the change in x. The capital greek letter delta (Δ) is used to represent the change in a variable.

Absolute Value

The notation for taking the absolute value is two vertical lines on either side of the expression being evaluated.

Square Root

The radical symbol by itself is used to denote taking the square root of a number.

A radical is used to represent fractional exponents. By itself it is used to represent the square root of an expression, but it also is used to represent higher roots as well.

Exponent

In mathematics superscript text is used to indicate the exponent of some number.

Logarithm

Logarithms are often abreviated as "log" followed by a subscript number representing the base and the number that the logarithm is being applied to.

Factorial

The exclamation mark is used to represent the factorial of a number in mathematics. A factorial is a unary operator.

Summation

The capital Greek letter Sigma is used to represent the summation operator in mathematics.

Product

The capital Greek letter Pi is used to represent the product operator in mathematics. The operator has three parts: an initial value, an end value, and the expression being evaluated.

## Logic

Equal

Two stacked horizontal lines respresents the equals symbol in mathematics. The two expressions on either side are equal, or the same, when the equal sign is placed in between them.

Greater Than

The symbol > represents the logical expression that the left side is greater than the right side.

Greater Than or Equal

The symbol for a less than or equal to is ≥. It combines the greater than symbol > and the equals symbol = together.

Less Than

The symbol < represents the logic expression that the left side is less than the right side.

Less Than or Equal

The symbol for a less than or equal to is ≤. It combines the less than symbol < and the equals symbol = together.

Not Equal

The symbol for not equal is a equal sign with a diagonal line through it.

Approximately

The symbol for approximately equal is a squiggly equals sign. It is used to show that two numbers are roughly equal, but not exactly equal.

## Geometry

Angle

The notation for a symbol is a small symbol written in text, sometimes followed by three letters that correspond to a figure.

Circle

Meaningful description here.

Parallel

Meaningful description here.

Perpendicular

The symbol for two perpendicular lines is a horizontal line with another line drawn perpendicular to it.

Triangle

Meaningful description here.

Theta

The symbol theta is often used as a variable to represent an angle in illustrations, functions, and equations.

Slope

Slope is denoted as the change in y over the change in x. The capital greek letter delta (Δ) is used to represent the change in a variable.

## Trigonometry

Angle

The notation for a symbol is a small symbol written in text, sometimes followed by three letters that correspond to a figure.

Perpendicular

The symbol for two perpendicular lines is a horizontal line with another line drawn perpendicular to it.

Triangle

Meaningful description here.

## Probability

Random Variable

In probability a random variable is denoted using capital latin letters usually X, Y, and Z or A, and B respectively.

Probability Distribution

A probability distribution is denoted like a function. Often a capital P is used for the function name, and the capital letter X is used for the argument to the function.

Conditional Probability

Conditional probability is denoted using a vertical bar between the two variables

Joint Distribution

A joint probability distribution is denoted like a function often using P as the function name. The capital letters X and Y are often used to represent the random variables of the distribution and are arguments to the function.

Expected Value

The expected value of a probability distribution is denoted as the function E(X).

Arithmetic Mean

The arithmetic mean of a data set is denoted by a horizontal bar over the variable x.

N Choose R Combination

The number of possible ways to choose r combinations from n total items is denoted using two parentheses with the n value above the r value. A subscript p or c is used to denote whether it is a combination or permutation.

N Choose R Permutation

The number of possible ways to choose r permutations from n total items is denoted using two parentheses with the n value above the r value. A subscript p or c is used to denote whether it is a combination or permutation.

Population Mean

Meaningful description here.

Standard Deviation

Meaningful description here.

Variance

Meaningful description here.

## Numbers

Set of Natural Numbers

Set of Integers

Set of Rational Numbers

Set of Real Numbers

2D Space

Three dimensional space is denoted using the symbol for the set of real numbers followed by a superscript three.

3D Space

Two dimensional space is denoted using the symbol for the set of real numbers followed by a superscript two.

Complex Number

A complex number is represented in two parts. The first is the real number part and the second is the imaginary number part.

Decimal Point

The decimal point is used to separate the whole part of a number from the decimal part. The whole part is represented using number digits to the left of the decimal point. The decimal part is also represented using digits to the right of the decimal point.

Set of Complex Numbers

Scientific Notation

Scientific notation ...

## Set Theory

Empty Set

An empty set is respresented as a zero with a diagonal line through it, or as an empty pair of curly braces.

Set

The notation for a set is two curly braces containing the elements of the set separated by commas.

Exists

The syntax for "there exists" is a backwards captial E. It is often used in conjuction with a variable with certain properties.

For All

An upside down capital "A" represents the for all symbol in mathematics.

Element of

The element of symbol describes membership to a set. When reading an equation the symbol can be replaced by saying "in".

Proper Subset

A proper subset is denoted by the subset symbol which looks like a U rotated ninety degrees to the right.

Proper Superset

A proper superset is denoted by the superset symbol which looks like a U rotated ninety degrees to the left.

Superset

The superset operator in set theory is denoted using the superset symbol which looks like a U turned ninety degrees counter clockwise with a horizontal line underneath.

Subset

The subset operator is denoted using a U shapes symbol rotated ninety degrees to the righ with a horizontal line underneath.

Intersection

The cap symbol is used in mathematics to represent the intersect operation for two sets.

Set Difference

The minus symbol is used in set theory to represent the difference operator for two sets. The operation removes all elements found in one set from another and returns the resulting set.

Union

The cup symbol is used in mathematics to represent the union operation for two sets. The union operator returns a set containing the elements from both sets.

## Boolean Logic

And

The "and" operator is denoted with the carrot symbol, which looks like a equilateral triangle with no bottom side. The operator evaluates to true if both the left and right expressions are true, otherwise evaluates to false.

Or

The logical or symbol describes when either one thing is true, the other thing is true, or both is true.

Equivalent

The equivalent operator is used to express that two expressions are equivalent, although not necassarily equal.

Implies

The boolean operator for implication is denoted using a double arrow pointing to the right.

Negation

The negation symbol is used to reperesent the unary operator for negation, which inverts the value of the expression it is applied to.

Xor

Xor is the boolean operator that describes the operation of exclusive or. For example, when a waiter asks whether you want orange juice or coffee, they are really asking an exclusive or: you can have one or the other, but not both.

## Linear Algebra

Vector

A variable that represents a vector often has an arrow over the top to indicate that it is a vector.

Magnitude

To vertical bars on either side of a vector represent taking the magnitude or length of that vector

Cross Product

In linear algebra the cross product operator is the times operator that is used in elementary mathematics.

Matrix

In Linear Algebra, a m by n matrix is denoted as a grid of numbers with two brackets on either side. The variable m corresponds to the number of rows, and the variable n corresponds to the number of columns.

Determinant

The syntax for a determinant is to vertical bars on either side of the matrix.

Scalar Product

The syntax for a scalar product is to angle brackets on either side of two vectors separated by a comma.

## Calculus

Limit

The syntax for a limit is a the abbreviation lim followed by the function or expression. Underneath the text, "lim", is the value the limit approaches.

Derivative

The first derivative of a function is denoted by a apostrophe after the function name. Alternatively the partial symbol can be used to represent the derivative with respect to a variable.

Integral

The notation for an integral in mathematics is a slanted vertical line with a start and end value that describe the range of the integral. This is followed by the function being integrated and the variable with respect to which the integral is being evaluated.

The nabla symbol is used to represent taking the gradient of a function.

## Computing

Array

An array is common data structure used throughout programming and computing.

a - b
Computing Subtraction

In computing subtraction is denoted using the hyphen symbol.

a / b
Division Computing

When entering an equation into a calculator or the computer the forward slash is used to represent division.

a ^ b
Exponent Computing

When computing an expression which contains the exponent operator, the caret symbol is often used in place of what normally would be superscript text.

a * b
Multiplication Computing

When entering an expression in a computer multiplication is represented using the asterisk symbol.