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n^2

Sum of series n^2



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The solution

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  oo    
 ___    
 \  `   
  \    2
  /   n 
 /__,   
n = 1   
n=1n2\sum_{n=1}^{\infty} n^{2}
Sum(n^2, (n, 1, oo))
The radius of convergence of the power series
Given number:
n2n^{2}
It is a series of species
an(cxx0)dna_{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:
Rd=x0+limnanan+1cR^{d} = \frac{x_{0} + \lim_{n \to \infty} \left|{\frac{a_{n}}{a_{n + 1}}}\right|}{c}
In this case
an=n2a_{n} = n^{2}
and
x0=0x_{0} = 0
,
d=0d = 0
,
c=1c = 1
then
1=limn(n2(n+1)2)1 = \lim_{n \to \infty}\left(\frac{n^{2}}{\left(n + 1\right)^{2}}\right)
Let's take the limit
we find
True

False
The rate of convergence of the power series
1.07.01.52.02.53.03.54.04.55.05.56.06.50200
The answer [src]
oo
\infty
oo
Numerical answer
The series diverges
The graph
Sum of series n^2

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