Transfer functions are convenient representations to analyse cause-and-effect relationships of linear time-invariant dynamic systems. Traditionally, transfer functions are introduced using the Laplace transform. In this paper, we argue that the Laplace transform method is not a necessary prerequisite to understanding the topic 'transfer functions'. We offer an inquiry-based learning method to represent transfer functions without formally using the full machinery of Laplace transforms. The method is used in an introductory engineering course on system modelling and simulation at Aalborg University, Denmark. The paper also presents an initial assessment of the students' understanding of transfer functions without knowledge of Laplace transforms and the experiences gained from implementing inquiry-based learning in the course. Finally, we conclude with a discussion of the impact of CAS tools on mathematics and engineering science teaching and learning.