Didactic Sequences for teaching Quadratic Equations

With the idea of reducing the difficulty of learning mathematics is that I began to study the doctorate in education and in the work of my doctoral thesis I looked for a topic in mathematics that is used in most of the university and technical careers, staying with the concept of quadratic equations, basic topic and of great application. In the present work I try to improve the idea presented in the doctoral thesis, trying to make the reading more agile and hoping that the topic can be applied or improved by some reader.