I also had a couple of professors that did the exact same think for a course. Most of the professors gave away the slides of the course, and even more addition

I also had a couple of professors that did the exact same think for a course. Most of the professors gave away the slides of the course, and even more additional material; these ones gave nothing but a bunch of literally useless tables and charts, completely worthless for the exams. Needless to say, this textbook was the only and obligatory literature for the course.