Matlab assignment 1

NJIT Math 222, Spring 2018

Due week of February 19

Part A

Using the program pplane1, plot the direction field and several solutions to the ordinary differential equations

  1. The autonomous equation
    dxdt=x2sinx.\frac{dx}{dt}=x-2 \sin{x}.
  2. The autonomous equation
    dxdt=x12sinx.\frac{dx}{dt}=x-\frac{1}{2} \sin{x}.
  3. The non-autonomous equation
    dxdt=t2xx3.\frac{dx}{dt}=t^2 x-x^3.

It is up to you to pick the range over which you plot in xx and tt in order to see the behavior.

Print your answers to graphics files (From the ''File\tosave as'' menu in the figure window, no screenshots!). And hand them in on paper along with your answer to the following questions:

  1. What are all the equilibria of equation 1?
  2. Which of these are stable and which are unstable?
  3. Why do the results look so different in equations 1 and 2? Support your answer with math and graphs.
  4. Describe the long-term behavior of equation 3 in words.

Part B

See assignment here.

Download the MATLAB source by typing


at the MATLAB >> prompt.