<![CDATA[This study aims to analyze senior high school students’ geometric thinking ability in coordinating symbolic and graphical representations of quadratic functions assisted by GeoGebra. The research employed a qualitative approach with a case study design. The subjects were 30 students of Grade X Phase E1 at SMA Negeri 8 Muaro Jambi in the second semester of the 2025/2026 academic year. Data were collected through a geometric thinking ability test, semi-structured interviews, and documentation. The research instruments were validated by two experts in mathematics education before being used in the data collection process. The data were analyzed qualitatively through data reduction, data display, and conclusion drawing, while data credibility was ensured through technique triangulation. The findings showed that students’ geometric thinking ability varied across Van Hiele levels. Five students were at Level 0 or visualization, 14 students were at Level 1 or analysis, three students were at Level 2 or abstraction, and eight students were at Level 3 or deduction. Most students were at the analysis level, indicating that they were able to identify several properties of quadratic function graphs but had not fully explained the relationship between symbolic and graphical representations systematically. GeoGebra supported students in visualizing the relationship between quadratic equations and parabolic graphs dynamically. Therefore, the higher the students’ geometric thinking level, the better their ability to coordinate symbolic and graphical representations of quadratic functions.]]>
