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14/(49n^2-70n-24)

Sum of series 14/(49n^2-70n-24)



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The solution

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  oo                   
____                   
\   `                  
 \            14       
  \   -----------------
  /       2            
 /    49*n  - 70*n - 24
/___,                  
n = 1                  
$$\sum_{n=1}^{\infty} \frac{14}{\left(49 n^{2} - 70 n\right) - 24}$$
Sum(14/(49*n^2 - 70*n - 24), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{14}{\left(49 n^{2} - 70 n\right) - 24}$$
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
$$a_{n} = \frac{14}{49 n^{2} - 70 n - 24}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(14 \left|{\frac{5 n - \frac{7 \left(n + 1\right)^{2}}{2} + \frac{47}{7}}{- 49 n^{2} + 70 n + 24}}\right|\right)$$
Let's take the limit
we find
True

False
The rate of convergence of the power series
The answer [src]
7*Gamma(16/7)
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30*Gamma(9/7)
$$\frac{7 \Gamma\left(\frac{16}{7}\right)}{30 \Gamma\left(\frac{9}{7}\right)}$$
7*gamma(16/7)/(30*gamma(9/7))
Numerical answer [src]
0.300000000000000000000000000000
0.300000000000000000000000000000
The graph
Sum of series 14/(49n^2-70n-24)

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