Using GeoGebra in Correcting Errors in the Concepts of Extremum and Inflection Points

In this study, the effectiveness of GeoGebra in correcting the errors and understanding the right ones was examined by taking into consideration the extreme and turning points the possible errors according to expert opinions. The study was designed as a case study, one of the qualitative research methods. It was carried out with 11 prospective mathematics teachers studying in the 3rd grade of a state university in Turkey. In order to reveal the knowledge of prospective teachers of the extreme and turning points, 19 expressions of true-false and interrogative of their causes were presented to the prospective teachers in writing. Then, applications related to the extreme and the turning points were made with GeoGebra assisted education. After 3 weeks, 19 expressions, presented to the prospective teachers before the application, were presented to them again, and 3 prospective teachers were interviewed. The descriptive analysis method was used to analyze the data. According to the findings of the study, a general increase was observed in determining the errors and making the correct explanation after the application regarding the prospective mathematics teachers. The findings of the interviews show that prospective teachers generally found GeoGebra assisted application useful and that they made progress in this regard with this application