Texas Instruments TI-84 PLUS SILV Guidebook - Page 312

Finding the Calculated Maximum You can use a CALCULATE menu operation to calculate a local maximum of a function. To do this, pick a point to the left of where you think the maximum is on the graph. This is called the left bound. Next, pick a point to the right of the maximum. This is called the right bound. Finally, guess the maximum by moving the cursor to a point between the left and right bounds. With this information, the maximum can be calculated by the methods programmed in the TI-84 Plus. 1. Press y / to display the CALCULATE menu. Press 4 to select 4:maximum. The graph is displayed again with a Left Bound? prompt. 2. Press | to trace along the curve to a point to the left of the maximum, and then press Í. A 4 at the top of the screen indicates the selected bound. A Right Bound? prompt is displayed. 3. Press ~ to trace along the curve to a point to the right of the maximum, and then press Í. A 3 at the top of the screen indicates the selected bound. A Guess? prompt is displayed. 4. Press | to trace to a point near the maximum, and then press Í. Or, press 3 Ë 8, and then press Í to enter a guess for the maximum. When you press a number key in TRACE, the X= prompt is displayed in the bottomleft corner. Notice how the values for the calculated maximum compare with the maximums found with the free-moving cursor, the trace cursor, and the table. Note: In steps 2 and 3 above, you can enter values directly for Left Bound and Right Bound, in the same way as described in step 4. Chapter 17: Activities 305