Mister Exam

Other calculators


8^(n-1)/(n-1)!

Sum of series 8^(n-1)/(n-1)!



=

The solution

You have entered [src]
  oo          
____          
\   `         
 \      n - 1 
  \    8      
  /   --------
 /    (n - 1)!
/___,         
n = 1         
$$\sum_{n=1}^{\infty} \frac{8^{n - 1}}{\left(n - 1\right)!}$$
Sum(8^(n - 1)/factorial(n - 1), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{8^{n - 1}}{\left(n - 1\right)!}$$
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
$$a_{n} = \frac{8^{n - 1}}{\left(n - 1\right)!}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(8^{- n} 8^{n - 1} \left|{\frac{n!}{\left(n - 1\right)!}}\right|\right)$$
Let's take the limit
we find
False

False
The rate of convergence of the power series
The answer [src]
 8
e 
$$e^{8}$$
exp(8)
Numerical answer [src]
2980.957987041728274743592099
2980.957987041728274743592099
The graph
Sum of series 8^(n-1)/(n-1)!

    Examples of finding the sum of a series