Afunction is a relation where each input value is assigned one output value. of a function is the set of all input values, or x-values, for which the function is defined. of a function is the set of all output values, or y-values, for which the function is defined. to write the equation y = ax + b in function notation, for y.

A function is a relation where each input value is assigned to only one output value.

The domain of a function is the set of all input values, or x-values, for which the function is defined.

The range of a function is the set of all output values, or y-values, for which the function is defined.

To write the equation y = ax + b in function notation, substitute f(x) for y.