Dependent and independent variables
![In calculus, a function is typically graphed with the horizontal axis representing the independent variable and the vertical axis representing the dependent variable.[1] In this function, y is the dependent variable and x is the independent variable.](/uploads/202502/15/Polynomialdeg2.svg0831.png)
In mathematical modelling and statistical modelling, there are dependent and independent variables. The models investigate how the former depend on the latter. The dependent variables represent the output or outcome whose variation is being studied. The independent variables represent inputs or causes, i.e. potential reasons for variation. Models test or explain the effects that the independent variables have on the dependent variables. Sometimes, independent variables may be included for other reasons, such as for their potential confounding effect, without a wish to test their effect directly.