Texas Instruments TI-89 사용자 설명서

Differential Equation Graphing

 435

 t is not valid for either Axis when 

. If you select t, an Invalid axes 

error occurs when graphing.

Example of Time and Custom Axes

Example of Time and Custom Axes

Example of Time and Custom Axes

Example of Time and Custom Axes

Using the predator-prey model from biology, determine the numbers of rabbits and foxes 
that maintain population equilibrium in a certain region. Graph the solution using both 
time and custom axes.

X Axis, Y Axis Active only when Axes = CUSTOM, these let you select 

what you want to plot on the x and y axes.

t — time

y — solutions (y1, y2, etc.) of all selected differential 
equations

y' — values of all selected differential equations (y1', y2', 
etc.)

y1, y2, etc. — the solution to the corresponding differential 
equation, regardless of whether that equation is selected

y1', y2', etc. — the value of the right-hand side of the 
corresponding differential equation, regardless of whether 
that equation is selected