MATH 215 -- Elementary Differential Equations I/

MATH 255 -- Ordinary Differential Equations

Session: 2012W Term 1 (Sept.-Dec. 2012)


NOTE: The Math Club, sells packages for 10$ in the Math Annex one week before the Final Exams. The packages contain solutions of past Final Exam problems (a few solutions in the past contained some errors).



SECTIONS:


GRADING:  Your final grade will be based on your Term mark (50%) and common Final Exam (50%) for all sections.  No notes, books or calculators will be allowed for the Midterms or the Final Exam. Please note that the median Term mark of your section may be scaled to match the median Final mark of your section.

Midterms: There will be two Midterms approximately based on weeks 1-4 and weeks 4-9. See you Section's website for the exact time and location of your Midterms. The Midterms will worth  30-40% of your overall grade. See your Section for details.

Homework Assignments and/or Quizzes:
The will be weekly problem sets which either has to turned in or alternatively short quizzes written in class. The homeworks/quizzes will worth 10-20% of your overall mark. Please consult your section for details.

Policies:
Missing a midterm or an assignment will normally result in a mark of zero. Exceptions may be granted in two cases: prior consent of the instructor or a medical emergency. In the latter case, the instructor must be notified as soon as possible (preferably before the test), and presented with a doctor’s note immediately upon the student’s return to UBC.


COURSE OUTLINE - SUGGESTED PROBLEMS


I. Introduction

 1. Week of September 3: what is a DE, order, linear and nonlinear, solution, general solution, particular solution, direction field

Reading: Chapter 1.
Suggested Problems: p.7: 1,6  p.15: 7,8,12;  p.24: 18, 20.  
Due
: Sept. 14th

II. First order equations

 2. Week of September 10: Solutions of basic first order DE: separable, linear and exact equations

Reading: 2.1, 2.2, 2.6 (no integrating factors)
Suggested  Problems: p.39:. 3(c), 8(c), 16, 30   p.47: 1, 6, 9, 32(b)    p.99: 1, 2, 13, 15          

 3. Week of September 17: Modeling with DE, autonomous equations, existence and uniqueness of solutions

Reading: 2.4, 2.3, 2.5
Suggested  Problems: p.75: 1,3,28   p.59: 2, 4, 16, 18b, 23a-c  p.88: 3, 5, 15, 20 a-c, 22

III. Second order linear equations

 4. Week of September 24: Second order linear homogeneous equations, fundamental set of solutions, Wronskian

Reading:  3.1, 3.4.
Suggested  Problems: ; p.144: 1, 9, 13, 17, 23, 28; p.155: 1, 2, 12, 13, 26  
 

 5. Week of October 1: Constant coefficient linear homogeneous equations (characteristic equation: simple and double real roots)

Reading: 3.2, 3.3
Homework Problems: p.163: 2, 7, 17, 25 a-c, 35; p.171: 1, 14, 23, 25; Due:  Oct. 17th

6. Week of October 8: complex roots, reduction of order

Reading: 3.3-3.4 (continued)
Homework Problems:

7. Week of October 15: linear non-homogeneous equation: undetermined coefficients, variation of parameters, Midterm I: Oct. 19th Friday

Reading: 3.5, 3.6
Suggested  Problems: p.183: 1, 8, 17, 27, p.189: 1, 5, 13, 17, 19

IV. The Laplace transform

 8. Week of October 22: Applications to spring-mass systems (no electrical circuits, resonance or beat), Laplace transform: definition and examples, initial value problems

Reading: 3.7-8, 6.1, 6.2
Homework Problems: ; p.202: 3, 7, 11, 17,  p.215: 5, 12.  p.311: 5 a-b, 6, 7, 15; p.320: 3, 10, 12, 23
Due: Nov 2nd

9. Week of October 29:
step functions, discontinuous forcing functions, systems of first order equations: homogeneous case

Reading: 6.3, 6.4, 7.5,  (no matrix exponentials)
Suggested  Problems: p.328: 9, 13, 17, 21, 27;  p.336: 6a-b, 7a-b, 9,  p.398: 1(a), 4(a), 15, 18, 24, 26, 31
Calculators can be used for graphing!


V. Systems of first order linear equations

10. Week of November 5:
systems of first order equations:repeated and complex eigenvalues,

Reading: 7.6, 7.7, 7.8,
Suggested  Problems: p.409: 3, 5, 17, p.420: 3a, 6a-b, 12, p.428: 2, 4, (for parts a-b you just have to sketch the phase portrait and indicate its type), 6, 8a;


VI. Nonlinear systems

 11. Week of November 12:  Midterm II: Nov. 14th

Reading: 7.9, 9.1 non-homogeneous case: undetermined coefficients, variation of parameters, classification of linear systems Conservative systems,
Suggested  Problems: p.439 5, 6, 11   (variation of parameters); 1, 3, 7 (undetermined coefficients)
p.494: 2, 3, 6 (only parts (a) (b) (c) only the phase portraits, don't have to sketch x_1 versus t), 14, 16

 12. Week of November 19: fixed points, linear approximations to non-linear systems, simple pendulum,

Reading: 9.2, 9.3,
Suggested  Problems:
p.506: 2, 4, 6, 21, 24  p.516: 5, 7, 9, 13, 19a,c (find H(x,y))

13. Week of November 26: competing species equations, Review

Reading: 9.3, 9.4 (in part) Review
Suggested problems: p.531: 2(b-e), 4(b-e),  15c,


Further information/resources