Nguyen TD, Nguyen NA, Phan KA. Students’ problem-solving performance in geometric extremum tasks through an integrated vector and analytical approach. J. Elemen [Internet]. 2026 Aug. 6 [cited 2026 Sep. 6];12(3):809-26. Available from: https://e-journal.hamzanwadi.ac.id/index.php/jel/article/view/34344