Análise de erros em razões trigonométricas no triângulo retângulo: contribuições à prática docente

Abstract

This study has the purpose of investigating contribuitions for teaching practice from errors made by students from the first year of High School in problems involving trigonometic ratios in right triangles. This research is qualitative and due to its purposes, is characterised as a pedagogical research. The collection of data was made by the contribuition of 72 students from the first year of High School and one mathematic teacher from a public school in the state education network. For the collection of data, a questionnaire was used as an instrument. The analysis of students' errors indicate that their main difficulties lies on comprehending the questions' wording, representing the data with algebraic or pictorial language, defining trigonometic ratios and using them correctly. Regarding the researched teacher's technique, in some instances, it was noticeable that errors are still seen as a negative element in learning. Nevertheless, generally speaking the teacher made clear that errors enable self evaluation of her practice and it is an element which contributes to students learning. Thus, the errors' analysis enable the teacher to monitor more widely the teaching and learning process, allowing her to conduct her technique inside the classroom and to minimize students' difficulties.