find the radius of convergence and interval of convergence of
the series ∑ n=1 ~ ∞ (3^n)((x+4)^n) / √n
Please solve this problem with detailed process of solving.
I can't understand why the answer is [-13/3, -11/3)
I thought that the answer was (-13/3, -11/3].
Can you explain why that is the answer?