Trigonometric derivatives are fundamental in both mathematics and physics, yet their correct application, particularly the distinction between radians and degrees, remains a significant challenge for college students worldwide. This study identifies a widespread "blind spot" in understanding trigonometric derivatives and their…

Epistemological obstacle is emphasized in mathematics education. Students often have limited students' context of knowledge in understanding trigonometry. Knowing the epistemology obstacle can help a teacher understand the student's misconception. Therefore, this study aimed to identify students' epistemological obstacles of trigonometry and…