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Sum of series (3^x+2^x)/x!



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The solution

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  oo         
____         
\   `        
 \     x    x
  \   3  + 2 
  /   -------
 /       x!  
/___,        
n = 0        
$$\sum_{n=0}^{\infty} \frac{2^{x} + 3^{x}}{x!}$$
Sum((3^x + 2^x)/factorial(x), (n, 0, oo))
The radius of convergence of the power series
Given number:
$$\frac{2^{x} + 3^{x}}{x!}$$
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
$$a_{n} = \frac{2^{x} + 3^{x}}{x!}$$
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]
   / x    x\
oo*\2  + 3 /
------------
     x!     
$$\frac{\infty \left(2^{x} + 3^{x}\right)}{x!}$$
oo*(2^x + 3^x)/factorial(x)

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