Background: The relevance of enabling beginning students of engineering courses to solve problems directly related to their future professional activities, already in the initial subjects of mathematics, implies the need to elaborate such problems, implement them and analyse their potential in terms of construction and application of mathematical knowledge in different contexts. Objectives: In this article, we analyse the cognitive dysfunctions evidenced by the students during the process of solving a problem articulating the real functions of a real variable to the study of the characteristic curve of a semiconductor diode, content linked to the analogical electronics. Design: This qualitative-nature investigation is characterised, as field research, of exploratory-descriptive combined type. Environment and participants: the research subjects, seven students in the first semester of an engineering course offered by a private institution in the state of São Paulo, with an interest in following the control and automation qualification, participated voluntarily in the study. Data collection and analysis: three synchronous meetings were held in remote modality. For data collection, we used audio and video recordings of the discussions and the written productions of the students in such moments. In this article, we present the analysis of the first meeting. Results: We evidenced, among other aspects, cognitive dysfunctions that can lead to obstacles in the transposition of mathematical knowledge to extra-mathematical contexts. Conclusions: The results obtained allow, in the future, the planning of adequate mediations so that the teacher can help the students to convert the identified dysfunctions into sufficiently developed cognitive functions.