Solved

Consider the Following Predator-Prey System Where X and Y Are dxdt=2x−xydydt=−4y+xy\begin{array} { l } \frac { d x } { d t } = 2 x - x y \\\frac { d y } { d t } = - 4 y + x y\end{array}

Question 49

Essay

Consider the following predator-prey system where x and y are in millions of creatures and t represents time in years: dxdt=2x−xydydt=−4y+xy\begin{array} { l } \frac { d x } { d t } = 2 x - x y \\\frac { d y } { d t } = - 4 y + x y\end{array}
(a) Show that (4, 2) is the nonzero equilibrium solution.
(b) Find an expression for dydx\frac { d y } { d x } .
(c) The direction field for the differential equation is given below:  Consider the following predator-prey system where x and y are in millions of creatures and t represents time in years:  \begin{array} { l }  \frac { d x } { d t } = 2 x - x y \\ \frac { d y } { d t } = - 4 y + x y \end{array}   (a) Show that (4, 2) is the nonzero equilibrium solution. (b) Find an expression for  \frac { d y } { d x }  . (c) The direction field for the differential equation is given below:   (i) Locate (4, 2) on the graph.(ii) Sketch a rough phase trajectory through P indicated in the graph.(d) With the aid of the phase trajectory, answer the following questions: (i) For the region  0 < x < 4  and 0 < y < 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(ii) For the region x > 4 and 0 < y < 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(iii) For the region x > 4 and y > 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(iv) For the region 0 < x < 4 and y > 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(e) Suggest a pair of species which might interact in the manner described by this system. (i) Locate (4, 2) on the graph.(ii) Sketch a rough phase trajectory through P indicated in the graph.(d) With the aid of the phase trajectory, answer the following questions:
(i) For the region 0<x<40 < x < 4 and 0 < y < 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(ii) For the region x > 4 and 0 < y < 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(iii) For the region x > 4 and y > 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(iv) For the region 0 < x < 4 and y > 2, is x (t) increasing or decreasing? Is y (t) increasing or decreasing? Describe in words how the two species interact with one another.(e) Suggest a pair of species which might interact in the manner described by this system.

Correct Answer:

verifed

Verified

(a) Solve the system of equations blured image (b) blured image ...

View Answer

Unlock this answer now
Get Access to more Verified Answers free of charge

Related Questions