In this paper, we present results obtained from the analysis of prospective high school teachers' mathematical practices about two tasks on derivatives. This analysis exemplifies the use and scopes of the notions of mathematical practices and configurations of objects and processes, provided by the Onto-Semiotic Approach (OSA) of mathematical knowledge, to characterize the knowledge of mathematics teachers. The analysis of the students' responses show both a disconnection between the different partial meanings of the derivative as well as the need to enhance the content knowledge through activities that encourage the use and identification of mathematical objects, their meanings, and the processes involved in the solution of mathematical tasks.
Teacher's Education; Teacher's Knowledge; Onto-Semiotic Approach; Mathematical Practices; Derivative
