# Definition:Dependent Variable

## Definition

### Real Function

Let $f: \R \to \R$ be a real function.

Let $\map f x = y$.

Then $y$ is referred to as a dependent variable.

### Complex Function

Let $f: \C \to \C$ be a complex function.

Let $\map f z = w$.

Then $w$ is referred to as the dependent variable (of $f$).

## Also known as

A dependent variable can also be referred to as a response variable.

## Also see

The terms independent variable and dependent variable arise from the idea that it is usual to consider that $x$ can be chosen independently of $y$, but having chosen $x$, the value of $y$ then depends on the value of $x$.