Math 23 Homework
Lectures 
Textbook Sections 
Course Topics 
Homework Exercises 
Day 1, Monday 3/29/21 
1.1, 1.2 
What are differential equations 
Section 1.1 Exercise 7, 9, 13, 23; Section 1.2 Exercises 1.a, 5, 11 Due Wednesday April 7 at 3 PM All the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 2, Wednesday 3/31/21 
1.3, 2.1 
Classification and linear firstorder ODEs 
Section 1.3 Exercises 1, 2, 7, 11; Section 2.1 Exercises 5, 15, 20 Due Wednesday April 7 at 3 PM All the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 3, Friday 4/2/21 
2.2, 2.4 
Separable equations and existenceuniqueness theorems. 
Section 2.2 Exercises 5, 7, 11.a, 23; Section 2.4 Exercises 3, 5, 11, 21 Due Wednesday April 7 at 3 PM All the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 4, Monday 4/5/21 
2.3 
Modeling with differential equations 
Section 2.3 Exercises 2, 3.a, 5, 7, 17.a, 17.b (to be considered as separate exercises) Due Wednesday April 14 to be submitted via Canvas, the whole week assignment should be one PDF file all the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 5, Wednesday 4/7/21 
2.5 
Autonomous equations and population dynamics 
Section 2.5 Exercises 1, 3, 7, 14, 25.a Due Wednesday April 14, all the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 6, Friday 4/9/21 
2.6 
Exact equations 
Section 2.6 Exercises 1, 9, 15, 19, 21, 22 Due Wednesday April 14, all the homework exercises for the whole week should be submitted in Canvas as one PDF file 
Day 7, Monday 4/12/21 
3.1 
Second order constant coefficient
equations 
Section 3.1 Exercises 3, 15, 17, 21 Due Wednesday April 21 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 8, Wednesday 4/14/21 
3.2, 3.3 
Complex conjugate roots 
Section 3.2 Exercises 7, 11, 15, 21 Section 3.3 Exercises 7, 19, 23 Due Wednesday April 21 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 9, Friday 4/16/21 
3.4 
Repeated roots and reduction of order 
Section 3.4 Exercises 5, 11, 14, 19, 21 Due Wednesday April 21 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 10, Monday 4/19/21 
3.5, 3.6 
Method of undetermined coefficients; Variation of parameters 
Section 3.5 Exercises 11, 13, 15, 25 Section 3.6 Exercises 9 and 11 Due Wednesday April 28 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Tuesday 4/20/21 First 2hour Midterm Exam 



Day 11, Wednesday 4/21/21 
7.1, 7.2 
Review of matrices. 
Section 7.1 Exercises 1, 3, 7, 15 Section 7.2 Exercises 1, 7, 9 Due Wednesday April 28 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 12, Friday 4/23/20 
7.3, 7.4 
Systems of ODEs; Existence and uniqueness of solutions of systems of ODEs. 
Section 7.3 Exercises 1, 7, 11, 15, 19 Section 7.4 Exercises 3 (parts a, b, c) to count together as one exercise and 3 (parts d, e, f to count together as a separate exercise), Exercise 5 (parts a, b, c only to count together as one exercise). Due Wednesday April 28 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 13, Monday 4/26/21 
7.5 
Constant coefficients systems with distinct real eigenvalues 
Section 7.5 Exercises 1 (using graphing devices is allowed), 7, 11, 13, 15 Due Wednesday May 5 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 14, Wednesday 4/28/21 
7.6 
Constant coefficient systems with complex conjugate eigenvalues 
Section 7.6 Exercises 3, 5, 7, 11, 17 Due Wednesday May 5 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 15, Friday 4/30/21 
7.8 
Repeated Eigenvalues 
Section 7.8 Exercises 1 (using graphing devices is allowed), 5, 7, 11, 13 Due Wednesday May 5 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 16, Monday 5/3/21 
7.8, 9.1 
Repeated eigenvalues; Phase plane; linear systems 
Section 9.1 Exercises 3, 7, 9, 11 Due Wednesday May 12 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 17, Tuesday 5/4/21 Xhour class instead of the Memorial Day 
9.1 and begin 7.9 
Phase Plane; Linear Systems 
Section 7.9 Exercises 3, 5 Due Wednesday May 12 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 18 Wednesday 5/5/21 
9.2 
Autonomous Systems and Stability 
Section 9.2 Exercises 5, 9, 15 (parts a and b only in all of the exercises 5, 9, 15 and usage of graphing devices is allowed when necessary) Due Wednesday May 12 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 19, Friday 5/7/21 
9.3, 9.4 
Locally Linear Systems 
Section 9.3 Exercises 5, 7 and Section 9.4 Exercises 3 (in this problem parts a, b, c will count together as one exercise and parts d, e, f together will count as a different exercise for the grading purposes). Due Wednesday May 12 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 20, Monday 5/10/21 
9.4, 9.5 
Competing Species and PredatorPrey Equations 
Section 9.5 Exercise 1 (parts a, b, c is one exercise for grading purposes) and part (d, e, f, g another exercise for grading purposes), Exercise 7 Due Wednesday May 19 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Second 2hour Midterm Exam Tuesday 5/11/21 



Day 21, Wednesday 5/12/21 
6.1. 6.2 
Laplace Transform and the IVP 
Section 6.1 Exercises 5, 11, 13 Section 6.2 Exercises 1, 5, 9, 13 Due Wednesday May 19 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 22, Friday 5/14/21 
6.3 
IVPs and Step function 
Section 6.3 Exercises 5, 9, 13, 21 Due Wednesday May 19 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 23 Monday 5/17/21 
6.4 
Discontinuous forcing functions, 
Section 6.4 Exercises 1, 7, 13, 15 Due Wednesday May 26 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 24, Wednesday 5/19/22 
6.5 
Impulse Functions 
Section 6.5 Exercises 1, 3, 13 Due Wednesday May 26 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file 
Day 25, Friday 5/22/21 
6.6 
The convolution integral 
Section 6.6 Exercises 1, 3, 5, 7, 11 Due Wednesday May 26 at 3 PM, all the homework exercises for the whole week should be submitted in Gradescope as one PDF file

Day 26, Monday 5/25/21 
10.1 
Twopoint boundary value problems 
Section 10.1 Exercise 1, 7, 11, 17 Due Wednesday June 2 at 3 PM, all the
homework exercises for the whole week should be submitted in Gradescope as one PDF file

Day 27, Wednesday 5/26/21 
10.2 
Fourier Series 
Section 10.2 Exercises 7, 13, 15, 19 Due
Wednesday June 2 at 3 PM, all the homework exercises for the whole week
should be submitted in Gradescope as one PDF
file 
Day 28, Friday 5/28/21 
10.3 
The Fourier Convergence Theorem 
Section 10.3 Exercises 3, 5, 15 Due Wednesday June 2 at 3 PM, all the
homework exercises for the whole week should be submitted in Gradescope as one PDF file

Monday 5/31/21 Memorial Day, No Class 



Day 29, Wednesday 6/2/21 
Course Wrap Up 


3 Hour Final Exam will be 811 AM on Sunday May 6 


