Math 231 –
Differential Equations
Fall
Semester 2009
Class 35
Fri Nov 20
1. Read
pp. 238-246.
2. Homework 13 due Monday:
11, 12, 15, 18, & 27 on p. 278.
Class 34
Wed Nov 18
1. Homework 13 due Monday:
11, 12, 15, 18, & 27 on p. 278.
2. Read pp. 238-241.
Class 33
Mon Nov 16
1. Continue
studying pp. 224 - 242.
2. Homework 12
due Wed: 6, 10, 15, 20, & 24 on p. 278. Note
(Tuesday morning note): #15 has complex roots; so skip it for tomorrow’s
homework.
Graded exams will be returned
Wednesday.
Class 32
Fri Nov 13
1. Read
pp. 224 - 242.
2. Practice 1, 2, 3, 4, 6, 7, 10, 16, & 21 on p. 278.
Graded exams will not be returned until
next Wednesday.
Class 31
Wed Nov 11
1. For
Friday, read in Chapter 10, read pp. 213 - 222.
2. Exam 2
today.
Class 30
Mon Nov 9
1. Exam 2 covering
Chapters 1-8 on Wednesday. (No
calculators)
One part of the exam will require
determining whether a differential equation is (1) separable, (2) linear, (3)
exact, or (4) none of these types
For example, see Problems 20 - 34 on
p. 211 f.
The
worksheet Classification
of ODEs & Suggested Solution Methods can help you
with such problems.
·
Exam 2 Fall 2008 (Caveat. The exam on
Wednesday will not necessarily look like this.
For example, Wednesday’s exam will include Chapter 7 whereas last year’s
did not.)
2. For
Friday, read in Chapter 10, read pp. 213 - 222.
(Quadratic formula )
Class 29
Fri Nov 6
1. In Chapter 10, read pp. 213 - 222.
Reminders:
· Homework 11 due
Monday: 16 & 18 on p. 189.
· Exam 2 covering
Chapters 1-8 will be Wednesday, Nov. 11.
One part of the exam will require
determining whether a differential equation is (1) separable, (2) linear, (3)
exact, or (4) none of these types. See
Problems 20 - 34 on p. 211 f.
The
worksheet Classification
of ODEs & Suggested Solution Methods can help you
with such problems.
·
Exam 2 Fall 2008 (Caveat. The exam on
Wednesday will not necessarily look like this.
For example, Wednesday’s exam will include Chapter 7 whereas last year’s
did not.)
Class 28
Wed Nov 4
1. Homework 11
due next Monday: 16 & 18 on
p. 189.
Reminder:
2. Exam 2 covering Chapters 1-8 will be
Wednesday, Nov. 11.
One part of the exam will require
determining whether a differential equation is (1) separable, (2) linear, (3)
exact, or (4) none of these types. See
Problems 20 - 34 on p. 211 f.
The
worksheet Classification
of ODEs & Suggested Solution Methods can help you
with such problems.
Class 27
Mon Nov 2
1. Change in date: Exam 2
covering Chapters 1-8 will be Wednesday, Nov. 11.
2. Turn
in “Homework 10” on
Wednesday.
3. Read
about Dirac delta functions: pp. 169-180.
4. Practice 16 on p. 189 f.
Class 26
Fri Oct 30
1. As you read pp. 159-168, you may wish
to use the Maple worksheet Modeling
Abrupt Changes.
2. Homework 10 due Monday: 14, 18, 22 on p. 155 f. Also, 2, 6, 10 on p. 186 f.
Class 25
Wed Oct 28
Announcement:
1.
Turn in today’s
homework on Friday.
Three of the problems were graded on
Homework 6. Check the others yourself
using the Homework Key.
However points are deducted if a problem is
not done or where no serious attempt is made.
One paper had no name on it.
Assignment for Friday:
1. In Chapter 7, read pp. 159-168.
2. Practice
16, 20, 21 on p. 156. Also, 1, 3, 5, 7,
9 on p. 186.
3. Homework 10 is
due Monday: 14, 18, 22 on p. 155. Also, 2, 6, 10 on p. 186.
Reminders:
Exam 2 will cover Chapters 1-8 and will be on Friday, Nov. 6.
Class 24
Mon Oct 26
1. Read pp. 135-141.
2. Links
for today’s class: Periodic table & E.
coli bacteria.
Announcements:
1. Midterm
Grades were calculated as follows: .60*[Exam 1] + .40*[
Average of Homeworks & Quizzes]. (Homeworks 6, 7,
& 8 were not included.)
2.
Two of the problems were graded on Homework 8.
Check the other three yourself with the
Homework Key.
Reminders:
1. Homework 9 is due Wednesday: 3, 4,
& 9 on p. 153 f.
2. Exam 2 will cover Chapters 1-8
and will be on Friday, Nov. 6.
** Fall Break Oct. 17 – Oct 25 **
Class 23
Fri Oct 16
1. Practice: 1, 3, 4, 7, 10 & 12 on p. 153 f.
2. Homework 9 is
due Wednesday, October 28: 3, 4, & 9 on p. 153 f.
Announcement.
1. Extra Credit (not required) is due at class time Monday, Oct. 26:
(a) Poiseuille’s law (medium difficulty): 71 on p. 47.
(b) Zyzzyvas problem (difficult) 35 on p. 212.
2. Exam 2 will cover Chapters 1-8
and will be held on Friday,
Nov. 6.
Class 22
Wed Oct 14
1. In Chapter 6, continue reading pp. 129-139.
2. Practice: 1, 3, 4, & 7 on p. 153 f.
Reminder
Homework
8 (due Friday): 22, 24, 27,
30, & 31 on p. 211 f.
Class 21
Mon Oct 12
1. In Chapter 6, read pp. 129-139.
2. Homework 8 (due
Friday): 22, 24, 27,
30, & 31 on p. 211 f.
Class 20
Fri Oct 9
1. In Chapter 8, read pp. 199-209.
2. Practice problems
starting on p. 210: 1,
2, 4, 5, 6, 8, 9, 10,
12, 13, 14, 16, 17, & 19. (blue = worked in class)
Reminders:
1. Homework 7 (due Monday):
Work the 3 problems at the end of “Total
Derivatives & Differentials”.
Staple
the Maple solutions to your pencil-and-paper solutions.
2. Graded exams will be returned Monday.
Class 19
Wed Oct 7
1. In Chapter 8, read pp. 191-198.
2. Homework 7 (due Monday):
Work all of the problems at the end of the Maple worksheet “Total
Derivatives & Differentials”.
Staple
the Maple solutions to your pencil-and-paper solutions.
3. Graded exams probably won’t be completed
until Monday.
Class 18
Mon Oct 5
Exam 1 covering Chapters 1, 2, 3, & 4.
Homework 6
is due Wednesday! See below.
Class 17
Fri Oct 2
1. Exam 1 on Monday covers Chapters 1, 2, 3, & 4.
The
following link is the first exam in the Fall Semester of 2007: Exam 1
Fall 2007.
And here is last year’s first test: Exam 1 Fall 2008.
2. Practice p. 126: 30, 31, 32, & 34.
3. Homework 6 (due next Wed): 6, 13, 21, 24, 27, 33, & 43 on
pp. 126-127.
Class 16
Wed Sept 30
1. Read pp. 103-122 in Chapter 5.
2. Practice p. 126: 1-9 (odd); 10, 12, 14, 16,
18, 23, 26, 27, & 28.
Reminder: Exam 1 will be on Monday and will cover
Chapters 1, 2, 3, & 4.
Class 15
Mon Sept 28
1. Begin reading Chapter 5.
2. Quiz 4 on Wed will be over Problems 1-7 on p. 100.
Note. You can check answers that are not in the
back of the book with the Maple worksheet Euler’s Method .
Announcement:
Pick up
Homework 5 Solution Key. Your graded
work will be returned Wed.
Class 14
Fri Sept 25
1. Study Chapter 4.
2. As you read
Chapter 4, go through the Maple worksheets Euler Polygonal Curves & Euler’s Method .
3. Quiz 4 on Wed will be over Problems 1-7 on p. 100.
Announcement:
Your
graded Homework 4 will be returned today.
Class 13
Wed Sept 23
1. Read Chapter 4 for Friday.
2. Homework 5 (due Friday):
Problems 10, 11, 14, & 15 on p. 87.
Announcements:
1. Pick up your graded Quiz 3.
2. Your graded Homework 4 will be returned
Friday.
Class 12
Mon Sept 21
1. Begin reading Chapter 4.
2. Practice 8 & 9 on p. 87.
3. Homework 5 (due Friday):
Problems 10 & 11 on pp. 86-87. (More will be assigned on Wed).
Announcements:
1. Pick up your graded Homework 3. Everyone began with 10 points. You lost points if you did not work #10 and
#25 correctly.
Moreover, points were deducted if the
“homework rules” were not heeded---also, if you did not attempt a problem.
Check
the other 3 problems yourself with the Solution Key that I handed out Friday.
2. 1st Announcement: Exam 1 will be on
Monday, Oct. 5.
Class 11
Fri Sept 18
1. Read pp. 73-84. As
you read, continue to work through the worksheet: Direction Fields and Solution Curves.
2. Quiz 3 Monday on Problems 1, 2, 3, 4, & 5 on pp. 85-86.
Note. I do not have Homework 3 graded yet but
please pick up a Solution Key today.
Class 10
Wed Sept 16
1. Read pp. 67-73. As
you read, go through the worksheet: Direction Fields and Solution Curves.
Reminder:
Homework 4 (due Friday):
51, 52, 55, & 58 on p. 64. (The solution of #55 is on p. 473, but find the differential
equation from whence the solution is derived
and use the method of separating variables to solve the
differential equation.
Also,
attach a Maple worksheet showing the solutions of 51 and 55 (with the problems
typed up as usual.)
Extra Credit. Problem 57 (the snowplow problem) on p. 65. (I will give no help on an “extra credit
problem” other than to clarify it.)
Class 9
Mon Sept 14
1. Practice p. 64: 46, 47, 48, 49, 53, & 56.
2. Homework 4 (due Friday): 51, 52, 55, & 58 on p.
64. (The solution of
#55 is on p. 473, but find the differential equation from whence the
solution is derived and use the method of separating variables to solve the
differential equation.
Also,
attach a Maple worksheet showing the solutions of 51 and 55 (with the problems
typed up as usual.)
Extra Credit. Problem 57 (the snowplow problem) on p. 65. (I will give no help on an “extra credit
problem” other than to clarify it.)
Class 8
Fri Sept 11
1. Read pp. 60-62.
2. Practice
p. 63: 18, 22, 28, 31, 37, 43, 44, &
47.
3. Homework 3 (due Monday): 10, 13, 25, 35, & 36 on p. 63.
Class 7
Wed Sept 9
1. Maple Assignment #1 (10 points) is due Friday: Submit
a short Maple worksheet with a title, your name and the name of the course and section,
such as M231B, the problems typed up, and the Maple commands with the Maple
solutions of Problems 1, 2, & 3 at the end of the “acquaint2”
worksheet.
2. Read
pp. 49-60.
3. Practice p. 63: 1-9 (odd); 11, 14, 16, & 17.
Monday, September 7 (Labor Day
Class 6
Fri Sept 4
1. Go over the Maple worksheet called
“acquaint2.” Right-click
on the following hyperlink acquaint2
and “Save Target As acquaint2.mw” on the Desktop.
2. Maple Assignment #1 (10 points)
is due next Friday
(September 11):
Create
a new Maple worksheet to work the 3 exercises at the end of “acquaint.”
3. Quiz 2 next Wednesday on
Problems 49-65 on p. 44.
Class 5
Wed Sept 2
1. Practice p. 44: 49-65 (all).
2. Quiz 2 Wednesday, Sept. 9
will cover the above practice problems.
Class 4
Mon Aug 31
1. Practice problems starting on p. 44: 9, 11, 39-42
(all), 43-48 (all).
2. Quiz 1 on Wednesday
will cover Table 1.4 and the above practice problems.
Class 3 Fri
Aug 28
1. Read pp. 35-42.
2. To read an article explaining tabular integration by
parts, click here.
3.
Practice p. 44: 43 & 45.
4.
Homework 2 (due Monday):
p. 43: 22, 28, 34, 38, and 47.
Class 2
Wed Aug 26
1. Read pp. 19-34.
2. Memorize
the standard integral formulas in Table 1.4 (which are the standard ones in
Calculus I & II).
3. Practice
p. 43: 1-35 (odd)
4. Homework 2 (due Monday): p. 43:
22, 28, 34, 38, + [more to come on Friday].
Reminder:
Homework 1 (due Friday) is to turn in starting on p. 43: 6, 14, & 16.
Class 1
Mon Aug 24
1. Read the handout: Information about M231.
2. Read
the Preface and pp. 1–19.
3. Practice
p. 43: 1-7 (odd), 13, 15, 17.
4. Homework 1 (due Friday) is to turn in starting on p. 43: 6, 14, & 16.
