Each system of differential equations is a model for two species that either compete for the same resources or cooperate for mutual benefit (flowering plants and insect pollinators, for instance). Decide which of the following systems describes the

1
Each system of differential equations is a model
for two species that either compete for the same
resources or cooperate for mutual benefit
(flowering plants and insect pollinators, for
instance). Decide which of the following systems
describes the competition model.

1. image
2. image

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2
Graphs of populations of two species are shown.
Describe how each population changes as time goes
by. Select the correct statement. image

1. At t 3 the population of species 1 reaches a
   maximum of about 200.
2. At t 2 the population of species 2 reaches a
   maximum of about 100.
3. At t 2 the population of species 2 reaches a
   maximum of about 190

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3
Populations of aphids and ladybugs are modeled by
the equations image , image . Find the
equilibrium solutions.

1. A9,000,L400
2. A10,000,L400
3. A8,000,L200

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4
We used Lotka-Volterra equations to model
populations of rabbits and wolves. Let's modify
those equations as follows image , image .
What is the significance for the equilibrium
solution W0, R5000?

1. Both populations are stable
2. In the absence of wolves, the rabbit population
   is always 5000
3. Zero populations

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5
A phase trajectory is shown for populations of
rabbits ( R ) and foxes ( F ). Describe how each
population changes as time goes by. image

1. At t C number of rabbits decreases to about
   1000.
2. At t B the number of foxes reaches a maximum of
   about 2400.
3. At t B number of rabbits rebounds to 100.

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