4. Consider the equation N,+1 = N, exp[r(1-N/K)] This equation is sometimes called an analog of...
x'=r (1 - 2 / 2 x where r and K are positive constants, is called the logistic equation. It is used in a number of scientific disciplines, but primarily (and historically) in population dynamics where z(t) is the size (numbers or density) of individuals in a biological population. For application to population dynamics ä(t) cannot be negative. If the solution (t) vanishes at some time, then we interpret this biologically as population extinction. (a) Draw the phase line portrait...
4. Problem 4, Chapter 1 The predation P(N) on a population N(t) is very fast and a model for the prey N() satisfies N2 dN dt P 1-exp where R. K, P and A are positive constants. By an appropriate nondimensionalisa- tion show that the equation is equivalent to du dT it where r and q are positive parameters. Demonstrate that there are three possible nonzero steady states if r and q lie in a domain in r. q space...
4. In class you discussed a model for fishery management based on the logistic equation with a parameterization of harvesting, N =EN (1-)-mN, N(0) = No where m is the fishing rate ("m" for mortality). With m = 0, there are two fixed points: Ni = 0 (unstable) and N = K (stable). With m > 0, the second fixed point becomes N = K(1 - m/r) <K (a) At what critical fishing rate, me, will the population die out?...
4. Consider the following function in R" f(Fi, n)=-1) k-1 Find the critical point of this function and show whether it is a local minimum, a local maximum, or neither 5. By examining the Hessian matrix, show that if f(x,y, ) has a local minimum at then g(z, y,) -f(x,y, ) must have a local maximum at that point. Likewise, show that if f has a local maximum, then g must have a local minimum at that point. (ro, yo,...
Population growth problems BIDE model: No.1 N, +(B + 1) - ( D Rates: b = B/N; d = D/N: E) Net growth rate: R = b-d Exponential growth (discrete): N, NR* where R = 1+b-d Intrinsic rate of increase: r = InR Exponential growth (continuous): N:Noe -or-dN/dt = IN Logistic growth 1. Suppose a species of fish in a lake is modeled by a logistic population model with relative growth rate ofr 0.3 per year and carrying capacity of...
Exercises 1. Verify equation (3) 2. Use the techniques of Section 13.7 and the fact that P(0) = 10 to solve equation (5). 3. The carrying capacity of Atlantic harp seals has been estimated to be C = 10 million seals. Let 1 = 0 correspond to the year 1980 when this seal population was estimated to be about 2 mil- lion. (Data from: Fisheries and Oceans Canada.) (a) Use a logistic growth model = kP(C - P) with k...
Consider the Laplace equation for a ball of radius R described in spherical coordinates (r, 0) 2 1 cot 72 0= n where is the zenith angle and assume u is independent on the azirnuth angle d. a) By separation of variables, derive two ordinary differential equations of r and w:= cos e given by 2 F" (r) +2rF (r) - n(n + 1) F, (r) = 0, (1 w2)G (w) - 2wG", (w) +n(n +1)G, (w) 0. (n 0,1,2,....
2. (30 pts) Consider the system of Figure 1 (m-2 kg, k 50 N/m, 0-30°). a) Obtain the equation of motion. b) Compute the initial conditions such that the system oscillates at only one frequency when Fa)-2sin10 c) Calculate the response of the system for F)-2sin10/, xo-0,-10 m/s. d) Calculate the response of the system for F)-108t), xo-0, -10 m/s. c) Calculate the response of the system for F(i)-2sin10+108(-2), x0-0, ao-10 m/s. nt Ft) Figure 1. Mass-spring system 2. (30...
Problem 1: Consider a 2nd order homogeneous differential equation of the form aa2y"(x)bay(x) + cy = 0 (1) where a, b, c are constants satisfy so that y(x) = x (a) Find and justify what conditions should a constant m to (1) is a solution (b) Using your solution to (1) Write these three different cases as an equation that a, b,c satisfy. Hint: Use the quadratic formula we should get three different cases for the values that m can...
please answer all prelab questions, 1-4. This is the prelab manual, just in case you need background information to answer the questions. The prelab questions are in the 3rd photo. this where we put in the answers, just to give you an idea. Lab Manual Lab 9: Simple Harmonic Oscillation Before the lab, read the theory in Sections 1-3 and answer questions on Pre-lab Submit your Pre-lab at the beginning of the lab. During the lab, read Section 4 and...