Previous Conceptions about Systems of Linear Equations: an Exploratory Study with University Students

Abstract

In this exploratory study, we focused on identifying first-year university students' prior conceptions regarding the concepts of linear equations and the system of linear equations (SLE) with two unknowns. The knowledge of these conceptions will serve to understand what students are learning and as a starting point for planning the teaching of the SLE content of m x n . For this, 24 engineering students who were studying Linear Algebra answered a questionnaire with open questions about the graphic representation of a linear equation with two unknowns and a 3 x 2 SLE, the number of solutions of a linear equation and a SLE, a particular solution of a SLE and what they understand by the solution of a SLE. Later we analyzed their written protocols based on the thinking modes of Linear Algebra: synthetic-geometric, analytical-arithmetic, and analytical-structural. Our results revealed that the students identified the linear equation with a straight line. However, misconceptions predominate regarding a linear equation's number of solutions or the quantity a SLE with two unknowns can have. In addition, we observed that in the students' arguments, the analytic-arithmetic mode prevails, and they express difficulty in transitioning to the synthetic-geometric mode when the task is presented in a different mode.

Linear Algebra; Systems of Linear Equations; University Education; Modes of Thinking