Students’ notions of elementary trigonometric ratios

Abstract

In this paper, we present some of the results of an exploratory study on the several ways of expressing and interpreting the trigonometric notions of sine and cosine by a group of 16-17 years old students. The aim of this research is to analyze the representations, concepts, notions and senses handled by students when describing the sine and cosine of an angle. From the analysis on the answers of this group of students emerge a categorization, whose relations are discussed and interpreted. The results show several types of representations and senses, some of which have already been recognized in previous studies, while some others are new. The scarcity of research related with school meaning of the sine and cosine provides an extra interest to the study.