Independent variable

Definition

An independent variable is a variable that represents the input or cause, typically denoted as $x$. It is the variable that you manipulate to observe how it affects the dependent variable.

5 Must Know Facts For Your Next Test

1. The independent variable is usually plotted on the horizontal axis (x-axis) in a graph.
2. It is the variable that you change or control in an experiment or function.
3. In a function notation $f(x)$, $x$ is the independent variable.
4. The value of the independent variable determines the value of the dependent variable.
5. When solving for functions, identifying the independent variable helps determine which values to substitute into your equations.

Review Questions

• What axis does the independent variable typically get plotted on?
• In the function notation $f(x)$, which part represents the independent variable?
• How does changing an independent variable affect a dependent variable?

Related terms

Dependent Variable: A dependent variable is a variable whose value depends on that of another. It is often denoted as $y$ and changes in response to changes in the independent variable.

Function Notation: $f(x)$ denotes a function named $f$ with $x$ being its input or independent variable.

Domain: The domain of a function is the complete set of possible values of the independent variable. For example, if $f(x) = x^2$, then all real numbers are part of its domain.