1. J

    Predator-prey system

    Hello, I have to solve the following task with predator-prey method. The dynamics of self-regulating "predator-prey" populations in the population is described by the model: dN1/dt = (a - bN2 - αN1); dN2/dt = (-c + mN1)N2 (1), where α is coefficient of internal victim struggle, and...
  2. F

    Numerical analysis- fixed point iteration method

    Q. Compute by the method of fixed point iteration a real root of the equation x^3 + x^2 - 1 =0 correct up to two decimal places. In the above problem if we take f(x)=0, then to solve it we can write f(x) in the form of x=g(x). Now g(x) can take three different forms. i) 1/sqrt(1+x) ii)...
  3. M

    Eulers Method - Please Check My Work

    Hiya, Just completed this task on rulers method. Can you please check it? Question: Use Eulers method to obtain a numerical solution for: dy/dx = y/x +x^2-2 x=1, y=3 range 1.0 to 1.5 intervals of 0.1 Thank You
  4. S

    A method to show there are infintely many Twin Primes

    This is an attempt at a Twin Prime Conjecture Proof, and is open to Peer Review. Abstract: Surfaces representing the primes and composites, the upper twin prime, the difference between squares, and the relations among them, are used to select input for a quadratic in such a way as to always...
  5. H

    Cantor diagonalization method

    Hi, I want to prove by using the cantor diagonalization method the following statement: the set of all injective functions from N to N (N being the set of all natural numbers), is uncountable. Thank's in advance.
  6. H

    Need help with stats homework, specifically constant comparative method and deviant.. analysis. The question is as follows: On page 341 the researchers stated, “As hypotheses develop regarding the relationships between categories, it is necessary to determine whether the data support the hypotheses. This technique is known as verification (Strauss & Corbin, 1990). If the...
  7. U

    Numerov method on a exponential grid mesh

    Hi there. I was trying to implement Numerov method for solving second order differential equations (you can see some information of Numerov algorithm at here: ). At the beginning I've used a uniform grid mesh, all points equally spaced. I'm...
  8. B

    Integration Questions: Trig Sub, Partial Fractions, Cover Method

    Hi, I have two questions (well 3 really): 1. to find the integral of 2/(y2 + 9y + 8) - do I use partial fractions? I can see the denominator factors to (y+ 8)(y+1). We were taught the cover method and I have read about it however still don't get it. I am so used to cross-multiplying long...
  9. B

    Matlab and Newtons method

    Hi, i have to to use newtons method to solve for a zero solution of f(x) = x-e^-x^-2. I get the iteration formula: x(k+1) = xk - f(xk)/(f'xk) and a first guess that x(0) = 0.5. can anyone help me write the code for the next iterations (does it contain a for loop?) i am am new to calculus...
  10. B

    Newton's Method

    Hi, I can understand the application of Newtons method, (I think) - however doesn't the equation call for the differentiation of f(x) ie the f'(x of k)? I have read through the other posts in relation to this method however remain confused. We have not done derivatives as yet. My equation is...
  11. K

    Predictor Corrector method with lagrange polynomials

    Hello! I have to build a predictor corrector method for y' = f(x,y) with the following information. Predictor: integrate the differential equation over (Xk,Xk+1). Approximate f(x,y) by a first order Lagrange interpolating polynomial based on the points Xk-2 and Xk-1 Corrector: integrate the...
  12. P

    Best statistical method for choosing an element who has Multiple properties

    I am looking for the best method that allows choosing the best element from a list of elements where each one had multiple properties, My exact goal is choosing the best program (Prog01 or Prog02 ..) from a set of six programs based on their multiple properties, As shown in this Picture: To...
  13. S

    Eulers method convergence

    Hi! I need some help with the following question: for what step length h does y'=-cy (where c is a constant) converge? What can you do to avoid problems with the step length? I have no clue of how to solve this problem, all I know is that the formula is yn+1=yn+hf(tn,yn) but I don't know how to...
  14. A

    Can you explain my method?

    I've been looking at the problemu_y + (2x+u)u_x - (x+2u)=0 \qquad u(x,0)=1-x I'm a little hazy on the exact justification of the method, but essentially I think I assumed that there might be a solution of the form u(x,y)=\phi\big(x-(2x+u)y\big) where u(x,0)=\phi(x) = 1-x. I then wrote{\mathrm...
  15. Q

    Using the Bisection Method???

    I included a picture of the problem.
  16. D

    Matlab code: solve Helmholtz equation with SOR method

    Hi, I try to solve Helmholtz equation with finite difference method and SOR method. But if I choose optimal value (B) not equal 1, I can't find that solution. (the answer is Inf) matlab code: nx = 6; ny = 6; dx=1/(nx-1); dy=1/(ny-1)...
  17. S

    Rayleigh-Ritz Method for Plate Buckling Boundary Value Problem

    Hello Everybody, I need some help if possible for the following problem. I want to calculate the deflection formula and the critical buckling load for a rectangular composite plate under uniaxial in plane load. The plate is clamped on the loaded ends and free on the unloaded...
  18. Khovansky

    Exercise: Net Present Value method =(

    Hello everybody. Please could you explain me how is gained "net cash flow" which is named "market value" in the first column. If I got it right it has to be calculated that way: (total material costs - 10% (of the new period saving) - 30000 - 8000 ) \ time period wich is eight years. Thank...
  19. A

    Shell method of washer method

    Is there any trick that anyone use to determine which method is the right one to use? Or is it just trial and error?
  20. A

    Finding bounds of integration for a disk method

    How did they get -3 and +3 for the bounds of integration? I got -2 and +2. My work is illustrated.