Mental structures for modeling the learning of the change of basis theorem for vectors

Drawing on APOS Theory as our theoretical and methodological framework, we investigate under a cognitive approach the mental structures necessary to build the vector base change theorem (CBVT). In order to analyse the way in which college students learn it, a genetic decomposition (DG) for the theorem was designed. Through three case studies, it is shown how individual students build the concept of coordinates of a vector, but also have difficulties to use it in the construction of the vector coordinates matrix. This difficulty is linked to the fact that they have not coordinated the processes involved in terms of the quantifier. Specifically, we point to difficulties in building the CBVT as an object and in establishing the determining role of the concept of linear combinations in the CBVT.