RUME 28
2026
Alexandria, Virginia
Investigating Student Understanding of the Infinitesimal vs. Limit Definition of Integration Through the Curious Placement of dx
Page: 1100
Integrals can be conceptualized with an infinitesimal or limit definition, and holding a certain conceptualization may change how someone frames and solves an integral problem. We present excerpts from two different interview studies where we asked second-semester calculus-based intro physics students integral questions. Student utterances and differing answers to these selected questions led us to define two conceptual resources concerning infinitesimals, which correspond to the different definitions of integration. This work highlights subtle differences in students’ interpretation of integration and areas for future study