Texas Instruments TI-89 User Manual

Page of 1008
3D Graphing
 404
Notes:
For more accurate estimates, increase the 
xgrid
 and 
ygrid
 Window variables. 
However, this increases the graph evaluation time.
When you animate the graph, the screen changes to normal view. Use 
p to toggle 
between normal and expanded views.
Implicit Plots
Implicit Plots
Implicit Plots
Implicit Plots
An implicit plot is used primarily as a way to graph 2D implicit forms that cannot be 
graphed in function graphing mode. Technically, an implicit plot is a 3D contour plot with 
a single contour drawn for 
z=0
 only.
Explicit and Implicit Forms
Explicit and Implicit Forms
Explicit and Implicit Forms
Explicit and Implicit Forms
In 2D function graphing mode, equations have 
an explicit form 
y=f(x)
, where y is unique for 
each value of x.
Many equations, however, have an implicit 
form 
f(x,y)=g(x,y)
, where you cannot explicitly 
solve for y in terms of x or for x in terms of y.
y is not unique for 
each x, so you cannot 
graph this in function 
graphing mode.