The Implementation of Lesson Study Using Discovery Learning Model and Students’Worksheet Based on Constructivism on Relations and Functions Material

The mastery of material concepts is the most fundamental point in learning mathematics. Mastering the right concepts will make it easier to learn the next material, so it is needed the depth and well concepts mastery. Based on the results of observations and interviews at Muhammadiyah 9 Junior High School of Semarang, it can be concluded that the students' difficulties in relation and function material are: 1) students cannot distinguish between relations and functions, 2) Students have difficulty in giving examples of functions and non functions, 3) The implementing functions in solving problem. Responding to the existing problems, we need a learning model that can provide opportunities for students to find concepts independently. Learning models that can be applied to overcome problems are discovery learning model. In order to the application of discovery learning is more maximal, it is necessary to be assisted by constructivism-based worksheets. The purpose of implementing lesson study is to improve the understanding of the concept of relations and functions. This study used a qualitative approach collaborated with descriptive analysis method. ) defining functions, 3) explaining relation and function, 4) distinguishing between relations and functions, 5) giving examples of relations and functions. The results shown that there is an improvement on the ability of understanding concepts about relations and functions.