Students’ ability to solve function problems by using handep cooperative learning model

The cultural dimension can be a solution to identify the difficulties by learning about relations and functions. This study aims describe students' reasoning function concept, variations on open-ended problems related domain–codomains formulas, examine effect of handep cooperative model ability solve problems. research used quasi-experiment method involving 68 students. Data were collected through an essay test analytical rubric. was tested problem-solving functions using analysis variance. Consequently, most students have good definitions domain–codomain terms perfectly, very varied solutions in solving for formulas. has significant mastery concepts. steps supported students’ reasoning. Keywords: Cooperative Learning, Domain-Codomain, Function Formula, Handep, Problem-Solving, Reasoning.