Paper Title
Analysis of Students Error in Proving Trigonometric Identities

Abstract
The objective of this study is to describe kinds of error that were done by mathematics students of State Malang University in proving trigonometric identities based on Watson’s criteria. This study is kind of qualitative research. The subject of this study are 33 mathematics students that contain 2 students with high mathematics skill, 3 students with medium mathematics skill, and 26 students with low mathematics skill.The data was obtained through ways of seeing the answer of students in complete three problems of proving trigonometric identities. The answers are analyzed descriptively to find out the student's error type. The results of this study are (1) Types of errors made by high mathematics skill subjects in proving trigonometric identities are improper procedures and skills hierarchy problems. (2) The types of errors made by medium mathematics skill subjects in proving trigonometric identities are improper procedures, indirect manipulations, skill hierarchy problems, and other categories; (3) The type of errorsmade by lowmathematics skill subjects in proving trigonometric identities are lost data, improper procedures, and indirect manipulation. Keywords - Error analysis, Trigonometric Identities, and Watson criteria.