Texas Instruments TI-89 Titanium User Manual page 379

During rotation, the axes expand or contract to fit the screen's width and height.
Note:
This causes some distortion as shown in the example.
3 3
z1(x,y)=(x y–y x) / 390
ψ
When , the z axis runs the height of
eye =0
the screen.
ψ
When , the z axis runs the width of
eye =90
the screen.
3D Graphing
In this example,
eye =20 and eye
q
ψ
eye = 0
ψ
eye = 45
ψ
eye = 90
z=10
=70
f
z=10
z= 10
ë
z= 10
ë
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