can someone tell me the general method to find the sum of the similar series, or show me an example, please!
Hello, wopashui!
Sorry, there is no general method.
Each problem requires a different approach.
We have: .
Applying Partial Fractions, we find that: .
Hence: .
And everything cancels out except: .
Therefore: .
The geometric series has the sum: .
Therefore: .
Therefore, diverges.
We have a geometric series with the sum: .
Therefore: .