Math 308/513 - Fall 2018, TR: 2:20-3:35, BLOC 128


For each of these assignments, you will be required to use either one of the Matlab commands "dsolve" and "ode45 or one of the Java programs "dfield" and "pplane" for plotting direction fields and phase portaits by John C. Polking for which I recommend the Dfield/Pplane user manual by Nancy Chen. Please turn in a hard copy of each assignment on the day specified. In order to obtain a hard copy of an assignment using dfield or pplane click on file and then on print. In order to obtain a hard copy of an assignment using dsolve, click on the little down arrow in the upper right corner of the command window and then click on print. Here is an example of a hard copy of a dsolve assignment.

Computer Assignment 1, Due September 6, 2018

Use dfield to plot the direction field for the differential equation in Section 1.1, Problem 11, for -2<t<2 and - 4<y<8.
Make sure that you can plot y'=ay(b-y) where a and b are given constants.
Include on the direction field the graphs of the solutions satisfying y(0)=-2, y(0)=2, and y(0)=6 with the values a=1 and b=4.
After downloading dfiled you can run it with:  java -jar dfield.jar

Computer Assignment 2, Due September 27, 2018

Use the Matlab* command "dsolve" to do Section 2.1, Problem 14. Then use dfield to draw the direction field for the DE in Problem 14 for -2<t<2 and - 4<y<4. Include on the direction field the graph of the solution of Problem 14.