Rotating and/or elevating the viewing angle – Texas Instruments TITANIUM TI-89 User Manual

Page 386

3D Graphing

386

For example, suppose you trace the paraboloid z(x,y) = x

+ .5y

graphed with the

indicated Window variables. You can easily move the cursor to a position such as:

Although the cursor is actually tracing the paraboloid, it appears off the curve because
the trace coordinates:

•

and

are within the viewing cube.

– but –

•

is outside the viewing cube.

Note:

QuickCenter lets you center the viewing cube on the cursor’s location. Simply

press

¸.

When

is outside the z boundary of the viewing cube, the cursor is physically displayed

zmin

zmax

(although the screen shows the correct trace coordinates).

Rotating and/or Elevating the Viewing Angle

In 3D graphing mode, the

eye

q and

eye

f Window variables let you set viewing angles that

determine your line of sight. The

eye

Window variable lets you rotate the graph around

that line of sight.

Trace cursor

Valid trace
coordinates