Biologists are modelling the population of an endangered species of fish in a river system. The indigenous population of the area are permitted to harvest 200 fish once a year in January as part of their culture. Data collected on a recent field trip in December indicate that there are 500 fish in the river system. The data also suggest that the following mathematical model should be used, dy = -2 + y (16 – y), %D dt where y is the population of fish in the river measured in hundreds at time t years after the next harvest. a The term y (16 – y) on the right-hand side represents the familiar logistic growth model. What is the significance of the -2 in this equation? dy b Show that the DE can be re-written as dt :-(y - 4) (y – 12), and write down the initial condition assuming that the harvest goes ahead. 24 3 3 C Show that (у — 4) (у 12) y - 12 4 -

Algebra & Trigonometry with Analytic Geometry
13th Edition
ISBN:9781133382119
Author:Swokowski
Publisher:Swokowski
Chapter7: Analytic Trigonometry
Section7.6: The Inverse Trigonometric Functions
Problem 94E
icon
Related questions
Question
15 Biologists are modelling the population of an endangered species of fish in a river system. The
indigenous population of the area are permitted to harvest 200 fish once a year in January as part of
their culture. Data collected on a recent field trip in December indicate that there are 500 fish in the river
system. The data also suggest that the following mathematical model should be used,
dy
= -2 + y (16 – y),
dt
where y is the population of fish in the river measured in hundreds at time t years after the next harvest.
a The term y (16 – y) on the right-hand side represents the familiar logistic growth model. What is
the significance of the -2 in this equation?
dy
b Show that the DE can be re-written as
-i (y - 4) (y
12), and write down the initial
=
condition assuming that the harvest goes ahead.
24
3
3
C Show that
(у —
4) (y
12)
y – 12
У — 4
d Hence solve the IVP in part b.
e According to this model, the fish in the river will die out. When will that be?
f i
ii It can be shown that the solution of the DE for this initial condition is
If the most recent harvest had not occurred, what would the initial condition change to?
4(3 + 7e)
y =
1 + 7e
Investigate what happens for this solution over time. Comment on the result.
Transcribed Image Text:15 Biologists are modelling the population of an endangered species of fish in a river system. The indigenous population of the area are permitted to harvest 200 fish once a year in January as part of their culture. Data collected on a recent field trip in December indicate that there are 500 fish in the river system. The data also suggest that the following mathematical model should be used, dy = -2 + y (16 – y), dt where y is the population of fish in the river measured in hundreds at time t years after the next harvest. a The term y (16 – y) on the right-hand side represents the familiar logistic growth model. What is the significance of the -2 in this equation? dy b Show that the DE can be re-written as -i (y - 4) (y 12), and write down the initial = condition assuming that the harvest goes ahead. 24 3 3 C Show that (у — 4) (y 12) y – 12 У — 4 d Hence solve the IVP in part b. e According to this model, the fish in the river will die out. When will that be? f i ii It can be shown that the solution of the DE for this initial condition is If the most recent harvest had not occurred, what would the initial condition change to? 4(3 + 7e) y = 1 + 7e Investigate what happens for this solution over time. Comment on the result.
Expert Solution
steps

Step by step

Solved in 5 steps

Blurred answer
Recommended textbooks for you
Algebra & Trigonometry with Analytic Geometry
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
College Algebra
College Algebra
Algebra
ISBN:
9781305115545
Author:
James Stewart, Lothar Redlin, Saleem Watson
Publisher:
Cengage Learning
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Algebra and Trigonometry (MindTap Course List)
Algebra and Trigonometry (MindTap Course List)
Algebra
ISBN:
9781305071742
Author:
James Stewart, Lothar Redlin, Saleem Watson
Publisher:
Cengage Learning
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781305652224
Author:
Charles P. McKeague, Mark D. Turner
Publisher:
Cengage Learning
Calculus For The Life Sciences
Calculus For The Life Sciences
Calculus
ISBN:
9780321964038
Author:
GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Publisher:
Pearson Addison Wesley,