Written from the perspective of the applied mathematician, the latest edition of this bestselling book focuses on the theory and practical applications of Differential Equations to engineering and the sciences.

Emphasis is placed on the methods of solution, analysis, and approximation. Use of technology, illustrations, and problem sets help readers develop an intuitive understanding of the material. Historical footnotes trace the development of the discipline and identify outstanding individual contributions. This book builds the foundation for anyone who needs to learn differential equations and then progress to more advanced studies.

**Chapter 1 Introduction 1**

1.1 Some Basic Mathematical Models; Direction Fields

1.2 Solutions of Some Differential Equations

1.3 Classification of Differential Equations

1.4 Historical Remarks

**Chapter 2 First Order Differential Equations **

2.1 Linear Equations; Method of Integrating Factors

2.2 Separable Equations

2.3 Modeling with First Order Equations

2.4 Differences Between Linear and Nonlinear Equations

2.5 Autonomous Equations and Population Dynamics

2.6 Exact Equations and Integrating Factors

2.7 Numerical Approximations: Euler’s Method

2.8 The Existence and Uniqueness Theorem

2.9 First Order Difference Equations

**Chapter 3 Second Order Linear Equations**

3.1 Homogeneous Equations with Constant Coefficients

3.2 Fundamental Solutions of Linear Homogeneous Equations; The Wronskian

3.3 Complex Roots of the Characteristic Equation

3.4 Repeated Roots; Reduction of Order

3.5 Nonhomogeneous Equations; Method of Undetermined Coefficients

3.6 Variation of Parameters

3.7 Mechanical and Electrical Vibrations

3.8 Forced Vibrations

**Chapter 4 Higher Order Linear Equations**

4.1 General Theory of nth Order Linear Equations

4.2 Homogeneous Equations with Constant Coefficients

4.3 The Method of Undetermined Coefficients

4.4 The Method of Variation of Parameters

**Chapter 5 Series Solutions of Second Order Linear Equations **

5.1 Review of Power Series

5.2 Series Solutions Near an Ordinary Point, Part I

5.3 Series Solutions Near an Ordinary Point, Part II

5.4 Euler Equations; Regular Singular Points

5.5 Series Solutions Near a Regular Singular Point, Part I

5.6 Series Solutions Near a Regular Singular Point, Part II

5.7 Bessel’s Equation

**Chapter 6 The Laplace Transform**

6.1 Definition of the Laplace Transform

6.2 Solution of Initial Value Problems

6.3 Step Functions

6.4 Differential Equations with Discontinuous Forcing Functions

6.5 Impulse Functions

6.6 The Convolution Integral

**Chapter 7 Systems of First Order Linear Equations **

7.1 Introduction

7.2 Review of Matrices

7.3 Systems of Linear Algebraic Equations; Linear Independence, Eigenvalues, Eigenvectors

7.4 Basic Theory of Systems of First Order Linear Equations

7.5 Homogeneous Linear Systems with Constant Coefficients?

7.6 Complex Eigenvalues

7.7 Fundamental Matrices

7.8 Repeated Eigenvalues

7.9 Nonhomogeneous Linear Systems

**Chapter 8 Numerical Methods**

8.1 The Euler or Tangent Line Method

8.2 Improvements on the Euler Method

8.3 The Runge-Kutta Method

8.4 Multistep Methods

8.5 More on Errors; Stability

8.6 Systems of First Order Equations

**Chapter 9 Nonlinear Differential Equations and Stability**

9.1 The Phase Plane: Linear Systems

9.2 Autonomous Systems and Stability

9.3 Locally Linear Systems

9.4 Competing Species

9.5 Predator-Prey Equations

9.6 Liapunov’s Second Method

9.7 Periodic Solutions and Limit Cycles

9.8 Chaos and Strange Attractors: The Lorenz Equations

**Chapter10 Partial Differential Equations and Fourier Series**

10.1 Two-Point Boundary Value Problems

10.2 Fourier Series

10.3 The Fourier Convergence Theorem

10.4 Even and Odd Functions

10.5 Separation of Variables; Heat Conduction in a Rod

10.6 Other Heat Conduction Problems

10.7 The Wave Equation: Vibrations of an Elastic String

10.8 Laplace’s Equation

Appendix A Derivation of the Heat Conduction Equation

Appendix B Derivation of the Wave Equation

**Chapter 11 Boundary Value Problems and Sturm-Liouville Theory**

11.1 The Occurrence of Two-Point Boundary Value Problems

11.2 Sturm-Liouville Boundary Value Problems

11.3 Nonhomogeneous Boundary Value Problems

11.4 Singular Sturm-Liouville Problems

11.5 Further Remarks on the Method of Separation of Variables: A Bessel Series Expansion

11.6 Series of Orthogonal Functions: Mean Convergence

Answers to Problems

Index

REVIEW