Guntharp, Marsha Nicol, Fred Browning, and Gloria Royle. 2017. “sing oy nimal all oppers to xplore rojectile otion in lgebra and alculus lasses”. hio ournal of chool athematics 74 (2). http://voyager.janeway.systems:9999/index.php/OJSM/article/view/5280.