and the independent variable 
but where neither variable is the subject of the equation. [M4.3, M6.1]
is: a function defined by an equation that relates the dependent variable and the independent variable but where neither variable is the subject of the equation. [M4.3, M6.1]
is exemplified: by the function 
defined by 
[M4.3, M6.1]
Copyright 1997, The Open University