THE TEACHER AND THE INTEGRATION OF THE GRAPHING CALCULATOR VIEWING WINDOW IN THE TEACHING OF MATHEMATICS

The use of graphing calculators in mathematics classes, confronts students and teacher with the choice of a suitable viewing window for the study of functions. Several studies have identified some of the difficulties usually faced by students in relation to their search for a suitable viewing window, however, we know very little about what the teacher does to help students overcome these difficulties. In this sense, this study aims to improve the knowledge and the understanding about the teacher's options regarding the way students interact with the viewing window during the study of functions at high school level. The study adopts a qualitative and interpretative methodological approach, undertaking one teacher case study. The findings of this study recognize the importance of carefully sequence the students' contact with situations in which the search for a suitable viewing window is more complex, but raise questions concerning how this confrontation should occur, suggesting that it is necessary to consider situations where the students actually face the difficulties, and placing a strong emphasis on the tasks proposed by the teacher. These findings also highlight the importance of identifying stages on teacher work with students around the viewing window and of including this knowledge in teacher education.