This book is a 2nd Edition and is intended to be an auxiliary text for undergraduate students in one-variable integral calculus. The book gives an approach to integrals of rational functions of sine and cosine, irrational functions and binomial, Euler, and improper integrals. It also lectures on reduction formulas and on the use of some integration tricks. On each subject, there are solved and proposed problems and the book contains two important appendices. The first appendix has an extensive collection of trigonometric formulas and formulas involving the logarithm and hyperbolic functions and their derivatives. The appendix b is about the integration of rational and irrational functions after their decomposition into proper rational functions.