About the book (back cover text):This book has been written with the notion that a wave is associated with a particle i.e. waveand particle coexist. Heisenberg's uncertainty principle has been described taking this intoaccount. This volume has a threefold purposes: [i] to explain the physical concepts ofQuantum Mechanics, [ii] to describe mathematical formalism, and [iii] to present illustrativeexamples of both ideas and methods. The book is intended as a text book on QuantumMechanics for undergraduate and graduate levels and also as a reference book for anyone whois interested in this field of enquiry. The book consists of 17 chapters. Particular interest of thereaders will be attracted to the chapters on Matrix formulation, variational and WKB methods,general angular momentum and their addition.Author biography (back cover text):The author is Dr Muhammad Alauddin Khan (alauddinkhan009472@gmail.com), AssociateProfessor, Department of Physics, Government M. C. College, National University, Sylhet3100, Bangladesh. He has been teaching Physics for more than 25 years for upperundergraduate and graduate students. The book is based on his lectures to the students.