In the field of mathematics education, the concept of a function is one of those that has been most studied, and this has been so from various perspectives. The present communication starts from describing some historical elements to go on to provide a thematic review of some of the research on this topic. In particular, work on the teaching and learning of the concept is discussed, followed by a focus on aspects relating to its exemplification. After considering briefly the role of examples in teaching and learning mathematics in general, two of their features are highlighted that are particularly relevant to teaching and learning the concept of function-variation and transparency.

problem solving, examples, function, secondary, mathematics teaching.