We are now using a "custom" text which is taken from the 9th edition
of the Boyce-Diprima book,
Elementary Differential Equations and Boundary Value Problems.
Sometimes students want to use the 8th edition, and the undergrad library
has both editions on reserve.
There are relatively few changes between the two editions in the sections
of the book used in Math 309. Professor Arms made a quick survey of these
sections and compiled the following list
of changes (excluding those that are small rewordings, such as converting a
list in paragraph form to a numbered list).
If you notice any other significant changes between the two editions
in the 309 material, please write to Professor Arms
(arms AT math.washington.edu).
Section 7.1: a predator-prey example in the 8th edition has been removed
from the 9th edition; in problems 8-12, the questions are the same but
are now split into parts a,b,c.
Section 7.1: no changes.
Section 7.3: text same, new problem 6 added so former problems 6 to 33
have been renumbered 7 to 34.
Section 7.4: no changes.
Section 7.5: Text same, problem content same, but instructions for problems
1 through 6 split into parts (a) and (b):
(a) Find the general solution of the gieven system of equations and describe
the behavior of the solution as t goes to infinity.
(b) Draw a direction field and plot a few trajectories of the system.
Section 7.6: text reorganized, problems the same.
Section 7.7: no changes.
Section 7.8: text same, problems 5 and 6 now ask only for the general solution,
rest of problems the same.
Section 7.9: no changes.
Section 9.1: no changes.
Section 9.2: substantial changes in text and problems, see 9th edition.
Chapter 10: minor rewording in Section 10.1; in Section 10.2, Example 2,
added discussion about the points of discontinuity of the
function; no other changes in rest of the chapter, including appendices, and
problems are the same.