This paper presents a conceptual analysis for students' images of graphs and their extension to graphs of two-variable functions. We use the conceptual analysis, based on quantitative and ...

A function is a rule that is applied to one set of values to give another set of values. A function can be illustrated on a graph – points are plotted as coordinates and joined by either a straight ...

An equation of the form \(y = mx + c\) where \(m\) and \(c\) are numbers, gives a straight line when values of \(x\) and corresponding values of \(y\) are plotted on a grid. A straight line is a ...

Forbes contributors publish independent expert analyses and insights. I help people communicate data clearly with graphs. I recently saw the infographic in Figure 1 and thought to myself, “Another ...