Alternating series

An alternating series is a type of infinite series in which the terms alternate in sign. Formally, a series of the form: \[ \sum_{n=0}^{\infty} (-1)^n a_n \] is called an alternating series, where \( a_n \) is a sequence of positive terms (i.e., \( a_n > 0 \)) for all \( n \).