"The book “New Pattern Differential Calculus for JEE Mains & Advanced” is the second edition of the first book from the TWIN BOOKS for CALCULUS in Mathematics for JEE Mains & Advanced. This book on Differential Calculus is the first attempt towards providing a logical and conceptual approach to solving problems for JEE Main & Advanced. The book is an attempt to provide the right mix of theoretical concepts, problem discussions through solved examples and exercises in the new IIT-JEE flavour. Each chapter starts with its Introduction which helps to understand the significance of each chapter. The theory moves along with a huge number of Illustrations which will help the students in mastering problem solving. The Illustrations (126 in all) are provided in a discussion format. At the end of theory of each chapter a list of useful tips is given which will be a very useful aid for the students in memorising the various formulae and concepts involved in the chapter.