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Sum of series ax



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The solution

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  oo     
 __      
 \ `     
  )   a*x
 /_,     
a = 3    
a=3ax\sum_{a=3}^{\infty} a x
Sum(a*x, (a, 3, oo))
The radius of convergence of the power series
Given number:
axa x
It is a series of species
aa(cxx0)ada_{a} \left(c x - x_{0}\right)^{a d}
- power series.
The radius of convergence of a power series can be calculated by the formula:
Rd=x0+limaaaaa+1cR^{d} = \frac{x_{0} + \lim_{a \to \infty} \left|{\frac{a_{a}}{a_{a + 1}}}\right|}{c}
In this case
aa=axa_{a} = a x
and
x0=0x_{0} = 0
,
d=0d = 0
,
c=1c = 1
then
1=lima(aa+1)1 = \lim_{a \to \infty}\left(\frac{a}{a + 1}\right)
Let's take the limit
we find
True

False
The answer [src]
oo*x
x\infty x
oo*x

    Examples of finding the sum of a series