You may have this scary looking upper case sigma before. But don't worry, it just means to add some things up! Once we understand how series work, we can do all kinds of other things. Also, have you ever seen numbers with exclamation points after them? No it, doesn't mean that you shout the number. Those are factorials! We will learn about those in here as well. Lots of good stuff in here! Watch the whole Mathematics playlist: Classical Physics Tutorials: Modern Physics Tutorials: General Chemistry Tutorials: Organic Chemistry Tutorials: Biochemistry Tutorials: Biology Tutorials: EMAIL► ProfessorDaveExplains@ PATREON► Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience! Amazon: Bookshop: Barnes and Noble: Book Depository: