Introduction to Differential Equations (Fall 2024)

(Math 305, MWF 8:00-8:50AM, EGRA 220)

9.     Tutoring session: ???

Instructor:  Dr. Dashun Xu

Office: 273 Neckers Hall A Wing
Office Hours: MW 8:50-9:55am, 10:50pm-11:50am, F: 8:50-9:55am, Th: 2-2:55pm, or by appointment

E-mail: dashunxu@siu.edu  Phone: 453-6512

Textbook:Elementary Differential Equations & Boundary Value Problems, by Boyce and  DiPrima 10th ed

 90   A 80   B 70   C 60   D 59   F

 Midterm exams 35 Homework 25 Final 32 Attendance (deduct 1 point per missed class meeting) 8

Important dates

 Semester Classes Begin Tuesday, January 16 Last Day to Register Sunday, January 21 Last Day to drop w/ Reg. Office Friday, January 26 Last Day to Drop with Refund Sunday, January 28 Spring Break Sat, March 9-Sun, March 17 Last Day to Drop w/o Refund Friday, March 29 Total Solar Eclipse (Classes Cancelled) Monday, April 8 Final Examinations Mon, May 6-Fri, May 10 Commencement Saturday, May 11

All assignments will be collected every Fridayin class and only a few questions in each assignment will be graded. Late homework will not be accepted. The followings are problems assigned last time. I will update these problems after each class meeting. Please make sure to refresh the webpage

 Date Homework Week 1 Please use the 10th edition of the textbook to do the homework problems. Otherwise, will be marked wrong! Week 2 Odd numbered 1, 3, 5,… 19 in Announcement 2   1.3: 1-6, 8, 9;; 2.1: find the general sol. to 1,3,5,7 2.1: (find the general solutions, i.e. part c ) 9,11, 13, 15,   2.2: 1, 2, 3, 5, 7, Due on Fri.   Please donot forget to staple your homework sheets together.   This webpage is updated according to the lecture pace on MWF. That is, you have to refresh this webpage to updated homework list. Week 3 Odd numbered 1, 3, 5,… 14 in Announcement 3   2.1: 17, 19;; 2.2: 13(a,c), 22; 2.9: 4, 10, 13 2.6: 3, 11, 13, 15 Week 4 2.6:9, 14 (find the solution); 2.6: (optional: 21; 22,) 2.6: 25, 26, 27, 28, 30;   2.4:  2, 5, 7, 11 2.4:  28, 29, 30, 31 Practice exam 1 (for you to review Chap 2)   HW due on Fri. Week 5 2.5: 3, 4, 7, 10 HW due on Fri.   Exam 1 on Fri in Week 6. Please review Chap1 and 2, and do the practice exam. Week 6 3.1: 1, 3, 9, 13, 15, 20 3.2:   9,  13, Optional: 3, 5, 11, 26 Exam 1 on Fri!!!   HW also due on Fri. Week 7 3.3: 7, 11, 17, 19, 21 Optional 9, 12, 15, 20 3.4: 7, 11, 13, 23, 27, 28, Optional: 12, 25, 29, 30, If possible, I still strongly recommend you to do all problems.   Due on Fri. Week 8 3.5: 1, 3,  16, 18 Week 9 3.5: 5.  7,  9, , 17, 3.5: 21(a, donot solve),  22a, 23(a), 24(a), 25(a)   3.5: Optional: 6, 8, 10, 19     3.6:  5, 7,  13,  17, optional: 3, 4, 14, 16, 18 Due on Fri. Week 10 4.1: optional: 14, 15, 16   4.2: 11, 14, 16, 18, 20, 22, find solution to IVP: 31; optional: 13, 18, 19, 24, 35 Week 11 4.2: 17, 19, 23, find solution to IVP: 29   4.3: 2, 3, 6, 9, 4.3: 13,  15, 16, 17,  Optional: 1, 10, 12, 14, 16, 18 HW due on Fri. Week 12 4.4: 2, 3,  9   10.1: 1, 3, 4 10.1: 14, 16, Optional: 2, 5, Homework due on Fri.   Please do the practice for chap3 and 4. I will check it in next Mon’s class. Week 13 10.1: 18   10.2: 13, 15 HW due also on Fri. Second Exam on Fri??? Covering Chap3, 4, and 10.1. Week 14 10.2: 14, 16 10.3: 1, 2, 3, 10.3: 7a, 9a, 11a Due on Fri 10.4: 7, 8, 9, 15, 16, 24(a,b)  10.5: 1, 2, 5, 6,     Optional: 10.5: 7, 8 after watching the video for 10.5. Week 15 Practice for the final: Midterm exams and their practice exams, homework problems for Chap10.2—10.5 Final exam:

Study Hint:

Find at least one or two other students from the class with whom you can regularly do homework and prepare for exams. Your classmates are perhaps the least used and arguably your best resource. An efficient and effective study group will streamline homework and study time and greatly improve your written and spoken communication. The best time to use your classmates as study/homework partners is after you have made an honest effort on your own to solve the problems using your own wits, knowledge, and experience. When you encounter an unsolvable problem, don't give up too soon on it. Being stumped is an opportunity for mathematical growth and insight, even if you never solve the problem on your own. If you seek help prematurely, you will never know if you could have solved a tough problem without outside assistance.