The concept of function is one of the central concepts in Mathematics; as such it has received attention in Mathematics Education Research. However, the research focused explicitly on the two subtopics of a function: Composition and Inverse. This study examined the use of graphical model to improve the performance of first year Diploma in Basic Education (DBE) students of Offinso College of Education, in Ashanti Region of Ghana. The study also investigated how the textbooks treated this particular topic and how teachers taught these two subtopics of a function. A total of fifty (50) students participated in the study. The data were collected through semi-structured interview and rating scale questionnaire. In addition to these, the students wrote pre-test and post-test. The data were analyzed in detail using quantitative and qualitative techniques. The results of the study suggested that, the performance of the students in the post-test was far better than the pre-test indicating that the intervention worked. Finally, the students’ interest was motivated and also developed confidence in solving composition and inverse of functions using graphical model. It is recommended that, constructivist theory of learning should be encouraged in all spheres of Mathematics classroom environments so as to give learners the opportunity to find meaning to their own learning in order to explore new ideas and findings concerning their future.
Keywords: Composition, Diploma in Basic Education (DBE), Inverse Function, graphical model
