MATH 3113- Introduction to Ordinary Differential Equations, Sections 001 and 002 (2015 Fall Semester)
The syllabus for this course is here. Office hours are 1pm-3pm Thursdays in PHSC 1007.
Here are answers for Test 1 in the 001 section and the 002 section
Here are answers for Test 2 in the 001 section and the 002 section I switched the problem 6 for the two sections by mistake! If you want to see the answer, look at the other section's problem 6.
Here are answers for Test 3 in the 001 section and the 002 section
Classes
August 26
Videos to watch before class:
1.1 Terminology
1.1 Modelling
1.2 General solutions of differential equations
1.2 Specific solutions of initial value problems
Homework I due August 28
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Section 1.1 Problems 2,8,21-22 (remember to sketch!) 33,36
Section 1.2 Problems 3,4
Here are Sections 1.1 and 1.2 from your book. I will not provide the textbook scans for future weeks, so please have the textbook by then!
August 28
Homework I due today
Videos to watch before class:
1.2 Velocity problems
1.2 Acceleration problems
1.3 Slope fields (8:23)
1.3 Slope field applet (3:09)
The link to the slope field applet in the above video is here.
If your computer doesn't like the security settings of the file and you don't know how to fix the problem, try this applet instead.
1.3 Sketching solutions of initial value problems(2:11)
Homework II due Sept 4
Section 1.2 Problems 12,15,28,31
Section 1.3 Problems 6-8,22
August 31
Videos to watch before class:
1.3 Sketching solutions of initial value problems(2:11)
1.3 Existence-uniqueness principle (3:51)
1.3 Existence-uniqueness example (4:43)
1.4 Separable equations (3:39)
1.4 Separable equations example (2:55)
Homework II due Sep 4
Section 1.3 6-8,11,13-14,22. Also do #15, except replace sqrt(x-y) with ln(x-y).
Section 1.4 3,7
September 2
Videos to watch before class:
1.4 The growth/decay equation (7:18)
1.4 Growth/decay equation example (7:29)
1.4 Population growth example (6:26)(optional)
Homework II due Sep 4
Section 1.4 20,33,35
September 4
Homework II due at the beginning of class
Videos to watch before class:
1.5 Integrating factors (6:39)
1.5 Integrating factors IVP example (8:15)
Homework III due Sep 11
Section 1.5 3,8,13
September 9
1.5 Mixing problems (5:02)
1.5 Mixing problem example (10:17)
Homework III due Sep 11
Section 1.5 33,36
September 11
Homework III due at the beginning of class
Please read this article. There is a chance that the quiz will be on this rather than on the videos!
1.6 Linear substitution example (6:12)
1.6 Homogeneous equations (4:41)
1.6 Homogeneous equation example (4:38)
Homework IV due Sep 18
Section 1.6 Problems 2,16,21
Septmeber 14
Videos to watch before class:
1.6 Bernoulli equations (3:30)
1.6 Bernoulli substitution example (8:57)
1.6 Reducible second order equations (4:50)
1.6 Reducible second order example with no y (5:16)
1.6 Reducible second order example with no x (4:49)
Homework IV due Sep 18
Section 1.6 Problems 46,49. In addition, please perform the appropriate u-substitution for 6,7,19,53. You don't have to solve those problems completely.
September 16
Midterm Test I
Extra office hours Tuesday 5-6pm
You may consult the web pages of my previous diff eq sections to look at past tests, by clicking on the "Teaching" tab on top of the page.
September 18
Homework IV due at the beginning of class
Videos to watch before class:
3.1 Second order linear differential equations (7:10)
3.1 The principle of superposition (8:06)
3.1 Existence-uniqueness principle for second order linear ODEs (3:56) (Optional)
3.1 Linearly independent functions (4:52)
3.1 General solutions for second order linear ODEs (8:13)
3.1 Wronskians and general solutions (4:12)
3.1 Finding a particular solution for a second order ODE (4:34)
Homework V due Sep 25
Section 3.1 6,12,17,21,27,30
Septmeber 21
Videos to watch before class:
3.1 Second order linear homogeneous ODes with constant coefficients (4:20)
3.1 Constant coefficients example (7:33)
3.1 When the characteristic polynomial has a repeated root (2:38)
3.1 Repeated roots example (3:03)
3.2 Double root explanation (7:51) (optional)
3.2 Higher order linear equations (7:00) (Everything after the 4:00 mark is optional)
3.2 Linear independence and Wronskians for n functions (6:42)
3.2 Linear (in)dependence exmaples (8:42)
Homework V due Sep 25
Section 3.1. 34,36,40,44
Section 3.2 1,3,7,9
Septmeber 23
Videos to watch before class:
3.2 General solutions for second order linear equations (4:01)
3.2 Example for finding a general solution for an inhomogeneous equation (3:43)
3.2 Linear dependence by calculating constants example (3:44)
Homework V due Sep 25
Section 3.2 17,24,25,27
Septmeber 25
Videos to watch before class:
Homework V due at the beginning of class
Videos to watch before class:
3.3 Homogeneous equations with constant coefficients (3:23)
3.3 Distinct real roots example (8:39)
3.3 Repeated real roots (3:13)
3.3 Repeated real root example (2:44)
Homework VI due Oct 2
Section 3.3 10,24,11, 26
September 28
Videos to watch before class:
Algebra review: Polynomial long division (2:59) (optional)
Solving a problem when knowing one root of the characteristic polynomial (2:04)
Homework VI due Oct 2
Section 3.3 28,33,39
September 30
Videos to watch before class:
3.3 Characteristic equations with complex roots (6:30)
3.3 Complex root example (2:00)
3.3 Repeated complex roots example (3:42)
Homework VI due Oct 2
Section 3.3 9,20,22,36
October 2
Homework VI due
Videos to watch before class:
3.4 Mass-spring models (10:48)
3.4 Undamped mass-spring motion example (7:26)
Homework VII due Oct 12
Section 3.4 2-3 (to find the amplitude, you might have to watch the Oct 5 videos)
October 5
Videos to watch before class:
3.4 Identifying overdamped and underdamped systems (1:38)
3.6 An amplitude formula(5:04)(optional)
Homework VII due Oct 12
Section 3.4 14,18,23 (for 14(a) and 18, you don't have to write the solution in that special cos(wt-a) form)
Additionally, for 16-17,19-21 just write down if the system is overdamped, underdamped, or critically damped.
October 7
Videos to watch before class
3.5 Method of undetermined coefficients (2:52)
3.5 Undetermined coefficients polynomial example (2:05)
Homework VII due Oct 12
Section 3.5 1,35
October 12
Homework VII due
Videos to watch before class
3.5 Undetermined coefficients trig example (5:00)
3.5 Variation of parameters (9:46)
3.5 Variation of parameters example (5:17)
3.5 Matching coefficients (3:34)
Homework VIII due Oct 16
Section 3.5 38,51,63
October 14
Videos to watch before class
3.6 Resonance(7:12)
3.6 Damped forced oscillations and practical resonance (9:12)
3.6 Practical resonance example (4:07)
Homework VIII due Oct 16
Section 3.6 16,18,19,20
OCtober 16
Homework VIII due today
Videos to watch before class
3.6 Steady periodic and transient solutions (2:48)
3.6 Transient and steady periodic solutions example Part 1 (8:14)
3.6 Transient and steady periodic solutions example Part 2 (5:48)
Homework IX due Oct 23
Section 3.6 12,13 (you don't have to write your solution in the cos(wt-a) form the book wants)
OCtober 19
Videos to watch before class
3.8 Introduction to endpoint problems (1:32)
3.8 Eigenvalues (6:36)
3.8 Eigenvalue example I (8:29)
3.8 Eigenvalue example II (5:15)
Homework IX due Oct 23
Section 3.8 1,5
October 21
Videos to watch before class
4.1 Systems of ODEs introduction (2:38)
4.1 Reducing a higher order DE to a system (4:21)
4.1 PPLANE tutorial (4:23)
Download the PPLANE java applet here.
We will also work out a short 3.8 problem, so it might be good to rewatch the March 9 videos.
Homework X due Oct 30
Section 4.1 3-4,13,15 (4th edition book numbering might be different for this chapter)
October 23
Homework IX due today
Videos to watch before class
4.1 Systems of ODEs introduction (2:38)
4.1 Reducing a higher order DE to a system (4:21)
4.1 Solving simple systems (1:34)
4.1 Simple systems example (5:40)
4.1 PPLANE tutorial (4:23)
Download the PPLANE java applet here.
Homework X due Oct 30
Section 4.1 3-4,13,15,19. You only have to print out the PPLANE screenshot for 19. 4th edition book numbering might be different for this chapter
October 26
We will continue with the material in Section 4.1. There will also be a review for the test in the remaining time
October 28
There will be additional office hours on Tuesday, October 27 5pm-6pm in PHSC 1007 for the test on Wednesday.
Principle of Superposition Review
Linear Independence Review
Constant Coefficients Review
Nonhomogeneous Equations Review
Unforced Spring Systems Review
Forced Spring Systems Review