An independent variable is a variable whose values don't depend on changes in other variables. This is in contrast to the definition of dependent variable. As with dependent variables, the notion of an independent variable comes up in a variety of contexts. In the case of univariate functions y = f(x), the input variable x is an independent variable. Similarly, x_1, ..., x_n are all independent variables in the case of the multivariate function y = f(x_1, ..., x_n).

dependent variable | parameter | variable