Texas Instruments TI-92 Getting Started page 21

Figure 5.61: Solving
The TI-92 is capable of shading the region above or below a graph, or between two graphs. For example, to graph
≥ 2 − , first enter the function y = x
y x 1
5.62). These keystrokes instruct the TI-92 to shade the region above y = x
The region above the graph will be shaded using the first shading option of vertical lines, as in Figure 5.63.
Now use shading to solve the previous inequality,
3 x
−
of and above x – 4. First graph both equations. Then, from the graph screen, press F5[Math] C[Shade]. The
1
2
TI-92 will prompt for the function that you want to have the shading above. Use
graph of x – 4, then press ENTER. The TI-92 will then prompt for the function that you want to have the shading
below, so use or to move the cursor to the graph of
the lower bound then the upper bound, which are the left and right edges, respectively, of the extent of the shading.
If you do not enter a lower or upper bound, the values of xmin and xmax will be used. So, in this case, press
ENTER twice to set the lower and upper bounds. The shaded area extends left from x = –2, hence the solution to
3 x
− ≥ −
1 x 4 is the half-line
2
2 1
Graphing Technology Guide: TI-92
3 x
− ≥ −
1 x 4
2
Figure 5.63: Graph of
2
– 1 as y1. Then, highlight y1 and press F6[Style] 7[Above] (see Figure
−
1
x ≤ , or (–∞, 2].
2
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Figure 5.62: Shade Above style
≥ 2 −
y x 1
2
– 1 . Press
3 x
≥ − . The solution is the region which is below the graph
x 4
2
3 x
−
and press ENTER. The TI-92 will then prompt for
1
2
GRAPH to see the graph.
or to move the cursor to the