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Sum of series (2*i+1)/n



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The solution

You have entered [src]
  oo         
 ___         
 \  `        
  \   2*i + 1
   )  -------
  /      n   
 /__,        
i = 1        
$$\sum_{i=1}^{\infty} \frac{2 i + 1}{n}$$
Sum((2*i + 1)/n, (i, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{2 i + 1}{n}$$
It is a series of species
$$a_{i} \left(c x - x_{0}\right)^{d i}$$
- power series.
The radius of convergence of a power series can be calculated by the formula:
$$R^{d} = \frac{x_{0} + \lim_{i \to \infty} \left|{\frac{a_{i}}{a_{i + 1}}}\right|}{c}$$
In this case
$$a_{i} = \frac{2 i + 1}{n}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{i \to \infty}\left(\frac{2 i + 1}{2 i + 3}\right)$$
Let's take the limit
we find
True

False
The answer [src]
oo
--
n 
$$\frac{\infty}{n}$$
oo/n

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