What Is "Limits and Infinite Series"? I signed up for my classes for spring quarter and I had room for another math class. Since I'm dual majoring in math and physics I figured I should take as much math as I could. I had to sign up for Multivariable Calculus I so I could take Electricity and Magnetism; but I also signed up for "Limits and Infinite Series" which is required for my math major. I did a bit of a google search with nothing really satisfactory; and the course description isn't very detailed: What exactly is "Limits and Infinite Series"? I'm aware it varies from college to college, but I know other college do have this course. What exactly does it cover? I guess I already know what a limit is from calculus; but an infinite series? I would guess that they're some sort of infinitely long expansion of sums that result in a finite number, like pi... Is the concept of an infinite series very useful in physics? I am interested in knowing where I would be able to apply this knowledge. Will it help with my study of E&M?