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Sum of series ln(1-3/n^2)



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The solution

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

False
Numerical answer [src]
-1.98728714190023218939231840466 + 3.14159265358979323846264338328*i
-1.98728714190023218939231840466 + 3.14159265358979323846264338328*i

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