  Students in introductory calculus-based physics not only have difficulty
understanding the fundamental physical concepts, they often have difficulty
relating those concepts to the mathematics they have learned in math courses.
This produces a barrier to their robust use of concepts in complex problem
solving. As a part of the Activity-Based Physics project, we are carrying out
research on these difficulties and are developing instructional materials in
the tutorial framework developed at the University of Washington by Lillian C.
McDermott and her collaborators. In this paper, we present a discussion of
student difficulties and the development of a mathematical tutorial on the
subject of pulses moving on strings.
