Introduction to series

An infinite series can be thought of as an attempt to add up an infinite collection of numbers. In this video we define the sequence of partial sums associated to an infinite series, as well as the notions of convergence and divergence for a series. The convergence of the geometric series 1 + 1/2 + 1/4 + 1/8 + ... is demonstrated using areas of rectangles. The series 1 - 1 + 1 - 1 + ... is used to motivate a discussion of why infinite series are such subtle creatures.