Texas Instruments TI-89 Manual Do Utilizador

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3D Graphing
 384
By displaying and labeling the axes, you can more easily see the pattern in the cursor 
movement. To move grid points closer together, you can increase Window variables 
xgrid
 and 
ygrid
.
When the trace cursor is on an interior point in the displayed plane, the cursor moves 
from one grid point to the next along one of the grid wires. You cannot move diagonally 
across the grid. Notice that the grid wires may not appear parallel to the axes.
Example of the Cursor on a Hidden Surface
Example of the Cursor on a Hidden Surface
Example of the Cursor on a Hidden Surface
Example of the Cursor on a Hidden Surface
On more complex shapes, the cursor may appear as if it is not on a grid point. This is an 
optical illusion caused when the cursor is on a hidden surface.
D
 moves in a negative 
y direction, back to ymin.
B
 moves in a positive 
x direction, up to xmax.
A
 moves in a negative 
x direction, back to xmin.
C
 moves in a positive 
y direction, up to ymax.
When you press 
, the trace cursor appears 
at the midpoint of the xy grid. Use the cursor 
pad to move the cursor to any edge.