CALCULATOR TI 84 PLUS GRAPHING TEX. NOTE: Some instructors allow students to use a graphing calculator app. See course notes (above) for instructors who allow this option. (iPhone app GraphNCalc83 app. Android option is Graphing Calculator Plus 84 83 by Lethinhien.) For directions and a guidebook on how to use this calculator, go to https://education.ti.com/en/guidebook/details/en/C4D11EB6D86B47D19CD768E54A967441/84p