Math 307 D:

Introduction to Differential Equations

Instructor: Sean Holman

Email: holmansf@math.washington.edu

Office: Padelford C-435

Office Hours: Thursday 2-4 pm, Wednesday 3-4 pm, or by appointment.

· Syllabus

· Homework/Lectures

· Here is some software (courtesy of John Sylvester) to assist you in plotting direction fields and solutions to differential equations. For homework problems that require you to create plots you may print the output. Please let me know if you have any trouble using the software.

· Here is a direction field plotter that uses Java.

Announcements:

• Monday, March 26. First day of class. If you didn’t get the Syllabus, please follow the link above. Also, don’t forget there is homework due the first week.
• Wednesday, April 4. I have now posted the homework assignment due on the 20^th, which includes problems from chapter 2 and chapter 3. Even though this assignment is not due until a week after the midterm, I strongly suggest that you do the problems from chapter 2 before the midterm in order to practice that material.
• Monday, April 9. Here is a solution to the first Challenge problem: page 1, page 2, page 3. Sorry it’s three pages long.
• Tuesday, April 10. Don’t forget that the first midterm is this Friday, the 13^th. I have made up a review sheet which you can find here.
• Saturday, April 14. Here are solutions to the midterm: problem 1, problem 2, problem 3, problem 4.
• Tuesday, April 17. I returned the midterms on Monday, but if you didn’t get yours then I will also have them in class tomorrow. Here are the statistics from the exam:

Average: 27/40

Top Quartile: 33-40/40

Median: 29.5/40

Bottom Quartile: 0-21/40

Approximate grades for various scores are as follows:

38/40 = 4.0

30/40 = 3.3

29/40 = 3.2

21/40 = 2.6

15/40 = 2.0

0/40 = 0

You can estimate your particular grade by linearly interpolating between these scores.

· Here are some notes (by John Sylvester) on complex numbers that may help you.

· Monday, April 23. Here is a solution to the second challenge problem.

· Wednesday, May 2. I have removed problem 10 from section 3.8 from the homework due on Friday, May 4. However, this problem will still be on the first homework assignment due after the midterm, and I highly suggest that you do it before the midterm.

· Monday, May 7. Here is a solution to the third challenge problem. Here are the diagrams to which the solution refers.

· Tuesday, May 8. Here is a review sheet for the second midterm. In order to save paper, I will not be making copies of this sheet to pass out in class.

· Monday May 14. Here are solutions for the second midterm: page 1, page 2, page 3, page 4. The statistics for the exam were as follows:

Average: 28/40

Top Quartile: 34-40/40

Median: 29/40

Bottom Quartile: 0-20/40

Here are approximate grades for some scores:

38/40 = 4.0

29/40 = 3.2

20/40 = 2.5

16/20 = 2.0

· Thursday, May 31. Here is a review sheet for the final. As with the second midterm I will not pass out copies in class.