anGiven the infinite series:
You need to remember that, by definition, given an infinite series:
(a) The formula for applying the Ratio Test is:
By definition:
1. If:
The series converges.
2. If:
Or:
The series diverges.
3. If:
The Ratio Test is inconclusive.
Therefore, you need to set up:
Simplifying, you get:
(b) Notice that:
Therefore, this indicates that the series diverges.
Hence, the answers are:
(a)
(b) It tells that the series diverges.