Applied mathematics is an interdisciplinary field that emphasizes on the creation and imaginative use of mathematical concepts to pose and solve problems spanning physical and biomedical sciences to engineering and social sciences. The study of applied mathematics seeks to quantitatively describe, predict, design, and control phenomena in a range of fields such as physics, engineering, medicine, biology, finance, business, computer science, and industry. It examines the relations between models and observations and at the same time scrutinizes the mathematical foundations and limitations of these models and techniques. The field of applied mathematics is associated with scientific computing, computer science, operations research and management science, statistics, actuarial science, and mathematical economics. This book provides comprehensive insights into the principles of applied mathematics. It presents this complex subject in the most comprehensible and easy to understand language. This book aims to serve as a resource guide for graduate students studying applied mathematics.