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0.9*10^n

Sum of series 0.9*10^n



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The solution

You have entered [src]
  oo       
____       
\   `      
 \        n
  \   9*10 
  /   -----
 /      10 
/___,      
n = 1      
$$\sum_{n=1}^{\infty} \frac{9 \cdot 10^{n}}{10}$$
Sum(9*10^n/10, (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{9 \cdot 10^{n}}{10}$$
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
$$a_{n} = \frac{9}{10}$$
and
$$x_{0} = -10$$
,
$$d = 1$$
,
$$c = 0$$
then
$$R = \tilde{\infty} \left(-10 + \lim_{n \to \infty} 1\right)$$
Let's take the limit
we find
False
The rate of convergence of the power series
The answer [src]
oo
$$\infty$$
oo
Numerical answer
The series diverges
The graph
Sum of series 0.9*10^n

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