One section of this book is called 'Equations of Several Colours'. In the 7th century, Brahmagupta used different colours to represent the unknowns in algebraic equations in the Brāhmasphuṭasiddhānta. In ancient works such as Euclid's Elements, single letters refer to geometric points and shapes. In mathematical logic, a variable is either a symbol representing an unspecified term of the theory (a meta-variable), or a basic object of the theory that is manipulated without referring to its possible intuitive interpretation. For example, the quadratic formula solves any quadratic equation by substituting the numeric values of the coefficients of that equation for the variables that represent them in the quadratic formula. Īlgebraic computations with variables as if they were explicit numbers solve a range of problems in a single computation.
A variable may represent a number, a vector, a matrix, a function, the argument of a function, a set, or an element of a set. In mathematics, a variable (from Latin variabilis, 'changeable') is a symbol that represents a mathematical object. For other uses, see Variable (disambiguation). For variables in computer science, see Variable (computer science).
