Texas Instruments TI-92 Getting Started page 13

If your range were set to a viewing rectangle extending from –10 to 10 in both directions, your graph would look
like Figure 5.31. Now this does not look a circle, because the units along the axes are not the same. You need what
is called a "square" viewing rectangle. Press F2[Zoom] 5[ZoomSqr] and see a graph that appears more circular.
Technology Tip: Another way to get a square graph is to change the range variables so that the value of ymax –
ymin is approximately times xmax – xmin. For example, see the WINDOW in Figure 5.33 to get the
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corresponding graph in Figure 5.34. This method works because the dimensions of the TI-92's display are such that
the ratio of vertical to horizontal is approximately
Figure 5.33:
The two semicircles in Figure 5.34 do not meet because of an idiosyncrasy in the way the TI-92 plots a graph.
5.2.5 TRACE: Graph the function y = –x
to clear any other functions in the Y= screen.) Press any of the cursor directions
from the center of the viewing rectangle. The coordinates of the cursor's location are displayed at the bottom of the
screen, as in Figure 5.35, in floating decimal format. This cursor is called a free-moving cursor because it can move
from dot to dot anywhere in the graph window.
Remove the free-moving cursor and its coordinates from the window by pressing
ENTER. Press the cursor pad again and the free-moving cursor will reappear at the same point you left it.
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Graphing Technology Guide: TI-92
Figure 5.32: Using y1 in y2
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vertical 18 3
= =
horizontal 42 7
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+ 4x from Section 5.2.2 using the standard viewing rectangle. (Remember
Figure 5.35: Free-moving cursor
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Figure 5.34: A "square" circle
GRAPH, CLEAR, ESC or
and see the cursor move