Functions of two variables can be visualized in many ways: heat maps in 2D, contour curves in 2D, wireframes in 3D, surfaces in 3D. We begin by defining a function of two variables, building an array ...

In this study we analyze students' understanding of two-variable function; in particular we consider their understanding of domain, possible arbitrary nature of function assignment, uniqueness of ...

Journal of the Royal Statistical Society. Series C (Applied Statistics), Vol. 30, No. 2 (1981), pp. 116-124 (9 pages) This paper develops a maximum likelihood method for estimating a piecewise ...