Microsoft Excel can perform numerous statistical functions, as well as create charts from statistical data. Statistical data includes numeric variables or word variables, also called categorical ...

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 ...

https://doi.org/10.4169/college.math.j.45.1.054 https://www.jstor.org/stable/10.4169/college.math.j.45.1.054 Summary We present a result of Rosenthal, which shows ...

Educational Studies in Mathematics, Vol. 73, No. 1 (Jan., 2010), pp. 3-19 (17 pages) This study is part of a project concerned with the analysis of how students work with two-variable functions. This ...