Esquema
Using Geogebra as a conceptual thinking tool
During my explanations I am using graphs, I know that this is not a deductive proof (we need a graph to infinity values to be absolute sure) but, it is a useful inductive tool to understand what is happening. It also helps to move away from solving things to understanding the structure of the problem. Normally when I am stuck, I start GeoGebra and seek visual cues.