196k views
2 votes
Determine if the following series converges or diverges. If it converges determine its sum.∞∑n=0 (−1)n

User Grumdrig
by
6.3k points

1 Answer

2 votes

Answer: The given series neither converges nor diverges.

Step-by-step explanation: We are given to determine whether the following series converges or diverges :


S=\sum_(n=0)^(\infty)(-1)^n.

If the series converges, we are to find its sum.

The given series can be written as :


1,~-1,~1,~-1,~1,~1,~~.~~.~~.

We note that the given series is a geometric one with first term 1 and common ratio given by


r=(-1)/(1)=(1)/(-1)=~~.~~.~~.~~=-1.

We know that a geometric series with common ratio r converges if |r| <1 and diverges if |r| > 1.

Since |r| = 1 for the given series, so the series will neither converge nor diverge.

Thus, the given series neither converges nor diverges.

User Seyeon
by
5.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.