Math 220: Differential Equations
Fall 2026
Department of Mathematics, Grinnell College
| Class # | Date | Reading | Brief description | Assignment |
|---|---|---|---|---|
| 1 | F Aug 28 | 1.1–1.3 | Introduction | -- |
| First Order ODEs | ||||
| 2 | M Aug 31 | 2.1 | Integrating Factor | -- |
| 3 | W Sep 2 | 2.2 | Separable Equations | Quiz 1 |
| 4 | F Sep 4 | 2.3 | Modeling with First Order ODEs | HW 1, Lab 0 |
| -- | M Sep 7 | -- | No Class -- Labor Day | -- |
| 5 | W Sep 9 | 2.5 | Autonomous ODEs and Population Dynamics | Quiz 2 |
| 6 | F Sep 11 | 2.6 | Exact ODEs | HW 2 |
| 7 | M Sep 14 | 2.7 | Euler's Method | -- |
| Second Order ODEs | ||||
| 8 | W Sep 16 | 3.1 | Homogeneous ODEs with Constant Coefficients | Quiz 3 |
| 9 | F Sep 18 | 3.3 | Characteristic with Complex Roots | HW 3, Lab 1 |
| 10 | M Sep 21 | 3.4 | Repeated Roots | -- |
| 11 | W Sep 23 | 3.5 | Method of Undetermined Coefficients | Quiz 4 |
| 12 | F Sep 25 | 3.7 | Mechanical and Electrical Vibrations | HW 4, Lab 2 |
| 13 | M Sep 28 | 3.8 | Forced Periodic Vibration | -- |
| 14 | W Sep 30 | -- | Q & A | -- |
| 15 | F Oct 2 | -- | Exam 1 | Exam |
| 16 | M Oct 5 | Notes | Introduction to Sequences and Series | -- |
| 17 | W Oct 7 | Notes | Introduction to Sequences and Series | -- |
| 18 | F Oct 9 | 5.1 | Review of Power Series | HW 5 |
| 19 | M Oct 12 | 5.2 | Series Solutions Near Ordinary Points | -- |
| 20 | W Oct 14 | 5.3 | Series Solutions Near Ordinary Points (cont.) | Quiz 5 |
| 21 | F Oct 16 | 5.4 | Euler's Equation -- Regular Singular Points | HW 6 |
| -- | Oct 17--25 | -- | No Class -- Fall Break | -- |
| The Laplace Transform | ||||
| 22 | M Oct 26 | 6.1 | Definition of the Laplace Transform | -- |
| 23 | W Oct 28 | 6.2 | Solution to Initial Value Problems | Quiz 6 |
| 24 | F Oct 30 | 6.3 | Step Functions | HW 7 |
| 25 | M Nov 2 | 6.4 | Discontinuous Forcing | -- |
| 26 | W Nov 4 | -- | More on Laplace Transforms | Quiz 7 |
| 27 | F Nov 6 | -- | Q & A | HW 8, Lab 3 |
| 28 | M Nov 9 | -- | Exam 2 | Exam |
| Systems of Linear Equations | ||||
| 29 | W Nov 11 | 7.1 | Introduction to Systems | -- |
| 30 | F Nov 13 | 7.5 | Constant Coefficients | -- |
| 31 | M Nov 16 | 7.6 | Complex Eigenvalues | -- |
| 32 | W Nov 18 | 7.7 | Fundamental Matrices and the Matrix Exponential | Quiz 8 |
| 33 | F Nov 20 | 7.7 | Fundamental Matrices and the Matrix Exponential | HW 9 |
| 34 | M Nov 23 | 7.8 | Repeated Eigenvalues | -- |
| 35 | W Nov 25 | 7.9 | Non-Homogeneous Linear Systems | Quiz 9 |
| -- | Nov 26--29 | -- | No Class -- Thanksgiving Break | -- |
| Stability | ||||
| 36 | M Nov 30 | 9.1 | The Phase Plane | -- |
| 37 | W Dec 2 | 9.2 | Autonomous Systems and Stability | Quiz 10 |
| 38 | F Dec 4 | 9.3 | Locally Linear Systems | HW 10, Lab 4 |
| 39 | M Dec 7 | 9.4–9.5 | Population Dynamics | -- |
| 40 | W Dec 9 | 9.7 | Periodic Solutions and Limit Cycles | Quiz 11 |
| 41 | F Dec 11 | 9.8 | Strange Attractors: The Lorenz Equation | HW 11, Lab 5 |
| -- | F Dec 18 | -- | Final Exam | Exam |
