Variable (mathematics)

In mathematics, a variable is an alphabetic character representing a number, called the value of the variable, which is either arbitrary or not fully specified or unknown.

Description

Making algebraic computations with variables as if they were explicit numbers allows one to solve a range of problems in a single computation.

Quadratic formula

A typical example is the quadratic formula, which allows one to solve every quadratic equation by simply substituting the numeric values of the coefficients of the given equation to the variables that represent them.

Calculus

The concept of variable is also fundamental in calculus.

Typically, a function y = f(x) involves two variables, y and x, representing respectively the value and the argument of the function.

Terminology

The term "variable" comes from the fact that, when the argument (also called the "variable of the function") varies, then the value varies accordingly.

Advanced mathematics

In more advanced mathematics, a variable is a symbol that denotes a mathematical object, which could be a number, a vector, a matrix, or even a function.

In this case, the original property of "variability" of a variable is not kept (except, sometimes, for informal explanations).

Computer science

Similarly, in computer science, a variable is a name (commonly an alphabetic character or a word) representing some value represented in computer memory. See Variable (computer science).

Mathematical logic

In mathematical logic, a variable is either a symbol representing an unspecified term of the theory, or a basic object of the theory, which is manipulated without referring to its possible intuitive interpretation.

See also

• Algebra
• Calculus
• Computer science
• Constant (mathematics)
• Equation
• Expression (mathematics)
• Mathematical logic
• Mathematical notation
• Mathematics
• Operation (mathematics)
• Quadratic formula
• Variable (computer science)

External links

• Variable (mathematics) @ Wikipedia