Texas Instruments TITANIUM TI-89 - Manual (Page 389)

3D Graphing 389
Effect of Changing eye Effect of Changing eye Effect of Changing eye Effect of Changing eye
f
phi phi phi phi
By changing eye f, you can elevate your viewing angle above the xy plane. If 90 < eye f <
270 , the viewing angle is below the xy plane.
Note: This example starts on the xy plane ( eye f = 90 ) and decrements eye f by 20 to
elevate the viewing angle.
Effect of Changing eye Effect of Changing eye Effect of Changing eye Effect of Changing eye ψ psi psi psi psi
The view on the Graph screen is always oriented along the viewing angles set by eye q
and eye f. You can change eye
ψ to rotate the graph around that line of sight.
z1(x,y) = (x
3
y – y
3
x) / 390
In this example eye q =
20
eye f = 90
eye f = 70
eye f = 50