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  • Sum of series:
  • (3/4)^n (3/4)^n
  • 1/((2n-1)*(2n+1)) 1/((2n-1)*(2n+1))
  • 1/(n*(n+3)) 1/(n*(n+3))
  • (5/6)^n (5/6)^n

  • Identical expressions

  • one /(two k- one)^2
  • 1 divide by (2k minus 1) squared
  • one divide by (two k minus one) squared
  • 1/(2k-1)2
  • 1/2k-12
  • 1/(2k-1)²
  • 1/(2k-1) to the power of 2
  • 1/2k-1^2
  • 1 divide by (2k-1)^2

  • Similar expressions

  • 1/(2k+1)^2
Sum of series/ 1/(2k-1)^2

Sum of series 1/(2k-1)^2


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The solution

You have entered [src] 
  oo            
____            
\   `           
 \        1     
  \   ----------
  /            2
 /    (2*k - 1) 
/___,           
n = 1
$$\sum_{n=1}^{\infty} \frac{1}{\left(2 k - 1\right)^{2}}$$ 
Sum(1/((2*k - 1)^2), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{1}{\left(2 k - 1\right)^{2}}$$
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
$$a_{n} = \frac{1}{\left(2 k - 1\right)^{2}}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty} 1$$
Let's take the limit
we find
True

False
The answer [src] 
     oo    
-----------
          2
(-1 + 2*k)
$$\frac{\infty}{\left(2 k - 1\right)^{2}}$$ 
oo/(-1 + 2*k)^2

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