Introduction to Differential Equations (Fall 2021)

(Math 305, MWF 9:00-9:50AM)

9.     Turtoring session: Mon-Thur, LIB 680 from 5:00-9:00pm

### Instructor:  Dr. Dashun Xu

Office: 273 Neckers Hall A Wing
Office Hours: MWF 11am-12:20pm, TTh 1:35-2:50pm, or by appointment

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

### Syllabus (Attachment for more useful webpage and dates)

Last Day to drop with Refund: Sun. Aug 29, drop w/Reg. office: Fri. Aug 27.

Last Day to drop w/o Refund: Sun. Oct 24.

### All assignments will be collected every Friday in 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.

 Date Homework Week 1 Week 2 1.3: 1-6, 8, 9;; 2.1: find the general sol. to 1,3,5,7, 8 2.1: 9,11(part c), 13, 15, 17, 19;; 2..2: 1, 2, 5, 6, 7, 13(a,c);; optional: 23 Due on Fri.   Please donot forget to staple your homework sheets together. Week 3 2.1: 8, 20; 2.2: find the solution to 14, 22; 2.6: 2, 3, 4, 5, 7, 8, 2.6: 9, 13, 14 (find the solution); 2.6: 18, 21; 22, 25, Practice exam 1 (for you to review Chap 2) Week 4 2.6: 26, 27, 28, 30; 2.4:  2, 5, 7, HW due on Fri. Week 5 2.4: 11, 28, 29, 30, 31 2.4: 31 2.5: 3, 4, 7, 10 HW due on Fri.   Exam on Fri!!!   As I said, I am going to collect Announcement 1, 2 and 3, and Practice exam 1 on Friday.   Of course also HW. Week 6 3.1: 1, 3, 9, 13, 15, 20 3.2:  3, 5, 9,  11, 13, 26 Due on Fri. Week 7 3.3: 12, 15, 3.3: 18,19, 22; 3.4: 7, 9, 10, 11, 13, 23,25, 27, Due on Fri. Week 8 3.3: 21 3.4:  12, 28, 29, 30, 3.5: 1, 5, 3, 6, 7, 8, 10, 15, 21-25(a) Week 9 3.5: 15, 16, 17, 18, 19. 3.6: 3, 4, 5, 7,  13, 14, 16, 17   4.1: 14, 15 Due on Fri. Week 10 4.2: 13, 16, 14, 17, 19, 22, 23, 24, 29, 31, 33, 35 Due on Fri Week 11 4.3:1, 3, 6, 9, 10, 4.3: 12, 13, 16, 18 4.4: 2, 3, 6, 9, 10 Week 12 10.1: 1, 2, 3, 4, 5, 14, 16, 18 Exam on Fri!   Homework due on Fri too. Week 13 10.2: 1, 2, 13, 14, 15 Due to no class on Fri, I collect HW on next Mon Week 14 10.3: 1, 2, 3, 10.3: 7a, 9a, 11a 10.4: 7, 8, 9, 15, 16, 24(a,b)   10.5: 1, 2, 5, 6 Cellect on Fri. (Dec. 3) Week 15 More practice problems 10.5: 7, 8   Practice for the final:   Midterm exams and practice exams   Now, You can watch my videos for Midterm exams in D2L. Final exam: 8—10am Fri. Dec. 10. AG168

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.