Texas Instruments TI-84 PLUS SILV Guidebook - Page 109

Chapter 6: Sequence Graphing Getting Started: Forest and Trees Note: Getting Started is a fast-paced introduction. Read the chapter for details. A small forest of 4,000 trees is under a new forestry plan. Each year 20 percent of the trees will be harvested and 1,000 new trees will be planted. Will the forest eventually disappear? Will the forest size stabilize? If so, in how many years and with how many trees? 1. Press z. Press to select Seq graphing mode. 2. Press y . and select Time axes format and ExprOn format if necessary. 3. Press o. If the graph-style icon is not ç (dot), press | |, press Í until ç is displayed, and then press ~ ~. 4. Press  ~ 3 to select iPart( (integer part) because only whole trees are harvested. After each annual harvest, 80 percent (.80) of the trees remain. Press Ë 8 y [u] £ „ ¹ 1 ¤ to define the number of trees after each harvest. Press à 1000 ¤ to define the new trees. Press † 4000 to define the number of trees at the beginning of the program. Note: Be sure to press y [u], not t [U]. [u] is the second function of the ¬ key. 5. Press p 0 to set nMin=0. Press † 50 to set nMax=50. nMin and nMax evaluate forest size over 50 years. Set the other window variables. PlotStart=1 Xmin=0 Ymin=0 PlotStep=1 Xmax=50 Ymax=6000 Xscl=10 Yscl=1000 Chapter 6: Sequence Graphing 102