A Course of Mathematics for Engineers and Scientists, Volume 4 focuses on mathematical methods required in the more advanced parts of physics and engineering. Organized into five chapters, this book begins by elucidating vector analysis and the differential and integral operations and theorems concerning vectors. Chapter II shows solution of ordinary and some partial differential equations. Chapter III addresses the properties of Bessel, Legendre, Laguerre, and Hermite functions that commonly occur in the solution of boundary and initial value problems. The last two chapters detail the differential equations of field lines and level surfaces, as well as the matrices. This book will be useful to undergraduate students so that they can appreciate and use the mathematical methods required in the more advanced parts of physics and engineering.