Cálculo no ensino médio: uma abordagem possível e necessária com auxílio do Software GeoGebra

Abstract

This piece of work has as its main objective, verifying the possibility of insertion in high-school, of the intuitive ideas of Differential and Integral Calculus applied to the study of quadratic functions. Intuitive ideas of limits of a function, average variation rate, instantaneous variation and even the calculus of areas below the graph of positive functions, limited by the abscissa axis and by vertical lines, or even among positive functions in a determined interval of domain of those, e.g. are fairly simple concepts, which can be inserted in high-school. In order to facilitate the understanding of those ideas, coupled to the study of functions, one can make use of a computational resource such as Geogebra, software used as a learning tool on the activities suggested in the present piece of work. The activities proposed here are intended to first-year students of high-school, ally to the study of quadratic functions, because of the need to restrict the theme on this occasion; however the proposed material may be adapted and applied to other functions studied in this series. Is to highlight the importance of introduction of those ideas in high-school, in a way that stimulates the construction of more solid knowledge about the behavior of functions and many other related concepts, such as consequences and the very construction of numerical conjuncts, especially real numbers. This way the student can expand, for example, his views on the construction of graphs from the idea of continuity of a function which may be approached by simple propositions involving the limits of a function and its behavior, insofar as we take values from its domain each time bigger or smaller. It s believed that, this way, on the long range, the students who entered in college education in the subjects of calculus, will have better conditions to understand the necessary concepts and, thus, the rate of failure in those subjects and other related, may not be so high. We will see in the course of this work, that the cause to that high rate of failure may be related to a faulty forming of intuitive ideas of calculus in high-school. The following piece of work presents a proposal of activities about the teaching of those topics with the aid of the software Geogebra and the analyses of the results of the applying of those activities on an experimental class of first-year high-school students. It s been verified that it s possible opening the horizons in the sphere of learning and teaching of mathematics in high-school, for the intuitive ideas of calculus, making use of several tools, such as the use of adequate technologies and that it s even possible providing the students with new methodologies of teaching that can favor the learning of those and other mathematical concepts.