Use the Point On Tool to Analyze Your TI-Nspire Graph
Some of the more common analyses that are performed on a graphed function on the TI-Nspire include evaluation, finding local maximum and minimum values, and locating zeros. The Point On tool offers a convenient way to accomplish each of these tasks. Here are the steps for using the Point On tool:
Press [MENU]→Points & Lines→Point On to open the Point On tool.
Use the Touchpad to move the cursor and click on the graph.
A ghosted image of the coordinates at this location appears along with the words point on.
Press [ENTER] or [CLICK] to create the point.
Press [ESC] to exit the Point On tool.
Hovering over the tool icon in the upper-left corner of the screen gives tooltips for how to operate each tool on a Graphs page.
Now move over the point until the grabbing hand symbol appears, and press [CTRL][CLICK] to grab the point. Using the Touchpad, move your point along the graph. Notice that when you approach a local maximum value, the word maximum appears accompanied by the coordinates of this local extreme value.
As you pass through a local minimum, you see the word minimum. As you pass through a zero (x-intercept) the word zero appears.
By default, the coordinate points are given with three significant digits. To change the level of precision, hover your cursor over the x-coordinate so that the grabbing hand symbol appears and the coordinate blinks. Press the [+] key repeatedly to increase the number of displayed digits, and press the [–] key to decrease the number of displayed digits. Repeat this process for the y-coordinate.
As you hover the cursor over the x-coordinate, try clicking [CLICK] twice to allow editing of the x-coordinate. Type a new x-coordinate value and press [ENTER]. Watch the point jump to its new location. You can also edit the y-coordinate.
For functions that are not one to one (meaning in some instances that the y-values are not unique), TI-Nspire jumps to a point with the specified y-value closest to the current location.