Graphing phase plots, Graphing with uv, vw, and uw, Example: predator-prey model – Texas Instruments TI-84 User Manual

Page 172

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Chapter 6: Sequence Graphing

169

Graphing Phase Plots

Graphing Phase Plots

Graphing Phase Plots

Graphing Phase Plots

Graphing with uv, vw, and uw

Graphing with uv, vw, and uw

Graphing with uv, vw, and uw

Graphing with uv, vw, and uw

The phase-plot axes settings

uv

,

vw

, and

uw

show relationships between two

sequences. To select a phase-plot axes setting, press

y ., press ~ until the

cursor is on

uv

,

vw

, or

uw

, and then press

Í.

Example: Predator-Prey Model

Example: Predator-Prey Model

Example: Predator-Prey Model

Example: Predator-Prey Model

Use the predator-prey model to determine the regional populations of a predator and its
prey that would maintain population equilibrium for the two species.

This example uses the model to determine the equilibrium populations of foxes and
rabbits, with initial populations of 200 rabbits (

u(nMin)

) and 50 foxes (

v(nMin)

).

These are the variables (given values are in parentheses):

Axes Setting

x-axis

y-axis

uv

u(n)

v(n)

vw

v(n)

w(n)

uw

u(n)

w(n)

R

=

number of rabbits

M

=

rabbit population growth rate without foxes

(.05)

K

=

rabbit population death rate with foxes

(.001)

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