Texas Instruments TITANIUM TI-89 User Manual

Page 351

Parametric Graphing

351

Selecting the Display Style

You can set the style for either the x or y component. For example, if you set the
x component to

Dot

, the TI-89 Titanium automatically sets the y component to

Dot

Note:

Use the

Animate

and

Path

styles for interesting projectile-motion effects.

The

Above

and

Below

styles are not available for parametric equations and are dimmed

on the Y= Editor’s

Style

toolbar menu.

Window Variables

The Window Editor maintains an independent set of Window variables for each

Graph

mode setting (just as the Y= Editor maintains independent function lists). Parametric
graphs use the following Window variables.

Note:

You can use a negative

tstep

. If so,

tmin

must be greater than

tmax

Variable

Description

tmin, tmax

Smallest and largest t values to evaluate.

tstep

Increment for the t value. Parametric equations are
evaluated at:
x(tmin)

y(tmin)

x(tmin+tstep)

y(tmin+tstep)

x(tmin+2(tstep))

y(tmin+2(tstep))

... not to exceed ...

x(tmax)

y(tmax)

xmin, xmax,
ymin, ymax

Boundaries of the viewing window.