The purpose of this paper is to report a part of a calculus research project, about the performance of a group of pre-service mathematics teachers on two tasks on limit and differentiation of the trigonometric sine function in which the unit of angle measurement was in degrees. Most of the pre-service teachers were not cognizant of the unit of angle measurement in the typical differentiation formula, and a number of participants recognized the condition on the unit of angle measurement but did not translate this to the correct procedure for performing differentiation. The result also shows that most of the participants were not able to associate the derivative formula with the process of deriving it from the first principle. Consequently, they did not associate it with finding  . In the process of evaluating this limit, the pre-service teachers exhibited further misconceptions about division of a number by zero.

During online learning, students were having difficulties in understanding the concept of the application of integrals to find an area. The provided materials in PowerPoint and learning sources such as books are still insufficient to understand the concept. The students’ feedback showed that a learning video is required to help the students understand the concept of the application of integrals. This research aims to develop a learning video concerning the concept comprehension of integrals’ application and determine its validity and practicality. This research utilized the analysis, design, development, implementation, evaluation (ADDIE) development model, where the subjects of this research were the students of mathematics education at the Ahmad Dahlan University. The data collection was conducted by using questionnaires and interviews. The obtained data was then analyzed for its validity and practicality. The media validity test result shows valid criteria with the assessment of the material expert of 4.629 (very good) and valid criteria with the material validity test of 4.735 (very good). The responses of the students to the learning video show 3.50 with the criteria of Very Good. Based on such results, this concept comprehension learning video is feasible to use.

Mathematical connection ability is very important to be mastered by prospective mathematics teacher students as competency to teach in secondary schools. However, the facts show that there are still many students who have weak mathematical connection abilities. This qualitative descriptive study aimed to explore how the process, and product of the mathematical connection made by prospective mathematics teacher students when solving the integral calculus problems based on their prior knowledge. The research subjects were 58 students who were prospective high school mathematics teachers at the University of Jember, Indonesia. Data were collected using documentation, questionnaire, test, and interview methods. After the test results of all subjects were analyzed, six students were interviewed. To find the match between the results of the written test and the results of the interview, a triangulation method was carried out. Data analysis used descriptive qualitative analysis with steps of data categorization, data presentation, interpretation, and making conclusions. The results show that the research subjects have connected and used mathematical ideas in the form of procedures, facts, concepts/principles, and representations in solving integral calculus problems. Students with high prior knowledge abilities can make better mathematical connections than students with moderate and low prior abilities. From these results, it is recommended that lecturers need to improve students' prior knowledge and train the students more intensely to solve integral calculus problems so all students can develop their mathematical connection abilities into very strong categories.