Connections in High School Mathematics Textbooks that Support Understanding of Key Features of Graphs of Functions

This study aims to evaluate a particular high school mathematics series of textbooks for its potential to adequately support teachers in emphasizing function-related connections. The investigation was limited to topics surrounding analysis of graphs of functions, specifically, domain and range; minima, maxima, and vertex; slope and increasing or decreasing intervals; and, intercepts and zeros. The chosen textbooks are McGraw-Hill’s Algebra 1, Algebra 2, and Precalculus textbooks with a copyright date of 2016. Each textbook was reviewed in sequential order. Items relating to the topics of interest were placed in a connection category and evaluated for nine different qualities. Data collected about the types of connections and the quality of those items reveals that the chosen textbooks have numerous connections among representations, but fewer connections to the real-world and across disciplines. Furthermore, a greater number of contextual items are included in Algebra 1 and Algebra 2 than in Precalculus.
Future investigations may aim to compare the series evaluated in this study to another series of mathematics textbooks. Additionally, teacher interactions with the textbook might provide more useful insights.