Effective questions when using dynamic graphs
Most graphing tools have a feature to add a variable constant in a way that can be changed dynamically. In Desmos and GeoGebra this is by using sliders; in Autograph it is via the constant controller. When the parameter is changed you can view its effect on the graph and this can be discussed with students. You can even animate the change so you don't need to do it manually! This feature of being able to dynamically change a variable constant is a very powerful tool to help students build their understanding; however, to make the best use of it, it is useful to have some questions to ask to direct students' thinking. Effective questions when using dynamic graphs When I vary … how does it move and why? For what value of … will …? If I vary … how will it move? Examples using the intersection of a line and a parabola To exemplify this I'm going to use the intersection of the parabola y = x 2 with the line y = mx+c . To do this I've plotted: y = x 2 y