Math 55 - Differential Equations

Sample Activities

Instructor: David Arnold

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Activities

  1. Finding A Model
  2. Numerical Methods I
  3. Numerical Methods II
  4. Modeling the US Population
  5. Latest version of Chapter 1, with Ken Menkveld's corrections. Chap1
  6. Fitting a Logistic Curve to Data

Abstracts and Materials

Finding a Model

Abstract

This activity requires that you visit the periodical stacks at Humboldt State University to find a model involving differential equations.

Prerequisites

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Numerical Methods 1

Abstract

This activity introduces students to solution technique available for the the numerical solution of first order ordinary initial value problems. In particular, euler's method, rk2, and rk4 are compared and contrasted. Because the approach is completely visual, students will need little, if any, prerequisite material before attempting this activity.

Prerequisites

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Numerical Methods II

Abstract

This activity introduces students to solution technique available for the numerical solution of systems of first order ordinary differential equations with initial conditions. In particular, euler's method, rk2, and rk4 are compared and contrasted. Because the approach is completely visual, students will need little, if any, prerequisite material on solving systems of ordinary differential equations before attempting this activity.

Prerequisites

Some familiarity with Matlab's plot command. Also, you will need to download eul.m, rk2.m, and rk4.m. The activity also uses Version 2 of the Symbolic Toolbox, a Matlab 5 interface to Maple. If you do not have the Symbolic Toolbox, you can use the solutions provided in the activity to continue with the numerical investigaiton.
 
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Modeling the US Population

Abstract

An introduction to population modeling, from Malthus to Verhulst and the logistic model. Matlab activities using real data are supplied.

Prerequisites

Some familiarity with Matlab's plot command. Also, you will need to download one decade semilogarithmic graph paper. Also, the file uspop.m contains the US census data used in this activity.
 
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Fitting a Logistic Curve to Data

Abstract

In this activity, we fit a logistic equation to a given set of data.

Prerequisites

Some familiarity with Matlab's plotting commands and array operators, although the article is completely self contained and should be accessible to anyone beginning in Matlab. You also need to get the article, "Fitting a Logistic Curve to Data," by Fabio Cavallini, which appears in the College Mathematics Journal, 1993, Volume 24, Number 3, Pages: 247-253.
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The Latex File
Matlab File
The Function File myerror.m