The graph of f is a line with slope m and y intercept b. Construct a function to model a linear relationship between two quantities. Linear Functions Any function of the form f (x) = m x + b, where m is not equal to 0 is called a linear function. Luckily, drawing a graph of a linear equation is pretty simple! Are you stuck not knowing how to draw a linear equation without using a calculator? Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Functions. How to Graph Linear Equations. 8.F.4. The domain of this function is the set of all real numbers. The range of f is the set of all real numbers.