Kesalahan Menggambar Grafik Fungsi Cosinus

: The purpose of this study is to describe the errors of the first semester students in drawing the graph of the cosine function and the factors that cause it. This research method uses qualitative research with a case study approach to 7 students of the mathematics education study program in one of the universities in Malang city. The data collected in this study were in the form of student work and transcripts of interviews with research subjects. Data analysis of student work is done by classifying errors based on the types of errors. Analysis of interview transcript data was carried out by coding words or sentences indicating the factors causing errors in drawing the graph of the cosine function. The results showed that the first semester students' errors in drawing the graph of the cosine function consisted of misconception, procedural errors, and factual errors. Misconception occurs due to a misunderstanding of the concepts related to the cosine function. A procedural error occurred when using the translation method to graph the cosine function. Factual errors are caused by not paying attention to the information contained in the questions.