Students determine a plan to maximize profit on a donut sale using data provided. The parabolic graphs of selling price vs.

Students determine a plan to maximize profit on a donut sale using data provided. The parabolic graphs of selling price vs. income and selling price vs. profit are used to explore intercepts, symmetry, and the vertex. The graphs and table allow for a side-by-side comparison of linear and quadratic functions. The goal is for students to link representations of data through tables and graphs and to see the connection to algebraic solutions. A quadratic rule is generated using the idea that income is selling price multiplied by number sold. This problem is suited to an introduction of quadratic functions after a study of quadratic equations. An activity sheet and solutions are included. This mathematically rich problem was developed for the Ohio Resource Center to accompany the Mathematics Program Models for Ohio High Schools proposed by the Ohio Department of Education. (author/sw)