Números complexos: uma abordagem voltada para professores do ensino médio

Abstract

This paper presents the complex numbers with an approach that we think to be appropriated for high school teachers. The aim is to provide one more text on the subject and assist high school teachers in their classes. We started working with a definition of complex numbers which includes the mathematical rigor necessary and seeks to maintain the simplicity required for this level of education. We used the geometric representation of a complex number, wherever possible, to motivate and simplify the definitions and demonstrations. We discussed the trigonometric and Moivre formulas emphasizing their importance. We presented the deduction of the formula for n-th root of a complex number. On the penultimate chapter, we discussed some issues that are not covered in mathematics textbooks from high school such as Euler’s formula, which the majority of applications of complex numbers exists because of this great discovery. The complex logarithm, whose theory explains how to calculate logarithms of negative or complex numbers and we also worked on complex powers, in such a way to explain how to calculate power number when the base and the exponent are complex numbers. Finally, we concluded this paper by analyzing some high school textbooks.