The main intended audience for this book is undergraduate students in
pure and applied sciences, especially those in engineering. Chapters 2
to 4 cover the probability theory they generally need in their training.
Although the treatment of the subject is surely su?cient for
non-mathematicians, I intentionally avoided getting too much into
detail. For instance, topics such as mixed type random variables and the
Dirac delta function are only brie?y mentioned. Courses on probability
theory are often considered di?cult. However, after having taught this
subject for many years, I have come to the conclusion that one of the
biggest problems that the students face when they try to learn
probability theory, particularly nowadays, is their de?ciencies in basic
di?erential and integral calculus. Integration by parts, for example, is
often already forgotten by the students when they take a course on
probability. For this reason, I have decided to write a chapter
reviewing the basic elements of di?erential calculus. Even though this
chapter might not be covered in class, the students can refer to it when
needed. In this chapter, an e?ort was made to give the readers a good
idea of the use in probability theory of the concepts they should
already know. Chapter 2 presents the main results of what is known as
elementary probability, including Bayes' rule and elements of
combinatorial analysis.