Introduction

We propose to investigate the construction of the trigonometric function from a perspective that challenges what the educational system ‘teaches’ and, consequently, how the student learns; this implies questioning not only how we teach, but what we teach. By means of the theoretical perspective of Socioepistemology [5, 6, 2] we intend to recognize the uses and significations associated with the trigonometric functions in a particular historical setting.

This theoretical perspective problematizes the knowledge confronting the mathematics of the educational system with the uses of knowledge in different settings, like historical, professional, or even school settings when experiencing non-traditional pedagogical proposals. The purpose of this paper is to recognize those significations that belong to knowledge but usually become diluted, altered or lost when setting up a school discourse.

There is a change from the didactical approaches concerned with the design of accessible presentations for school mathematics content or strongly centered on cognitive aspects to recognizing socio-cultural settings as part of the explanation of didactical phenomena. In this last paradigm, the socio-epistemological research framework focuses its attention on the normative role of social practices in the construction of mathematical knowledge: that which makes human individuals and groups do what they do [10].

This allows us to extend the didactical or cognitive explanations, dominant in the literature, about didactical phenomena related to the trigonometric functions. In this respect, before proposing educational innovations, we seek to recognize in the historical significations and uses, elements that help to explain didactical phenomena and then, based on epistemologies of practices, re-design the school mathematical discourse.