Mister Exam
Other calculators
- Taylor Series Step by Step
- Fourier series step by step
- Differential equations Step by Step
- Product of series
-
How to use it?
- Sum of series:
-
(n-1)/n!
-
(7^n-3^n)/21^n
-
1/(2*n-1)*(2*n+1)
- sqrt(n)*(x+3)^n/n^2+1
-
Identical expressions
- (n- one)/n!
- (n minus 1) divide by n!
- (n minus one) divide by n!
- n-1/n!
- (n-1) divide by n!
-
Similar expressions
- x^(n-1)/(n!)^(1/2)
- ((-1)^(n-1))/(n!)
- (n+1)/n!
Sum of series (n-1)/n!
The solution
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[src]
oo ___ \ ` \ n - 1 ) ----- / n! /__, n = 1
$$\sum_{n=1}^{\infty} \frac{n - 1}{n!}$$
Sum((n - 1)/factorial(n), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{n - 1}{n!}$$
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
$$a_{n} = \frac{n - 1}{n!}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(\frac{\left|{\frac{\left(n - 1\right) \left(n + 1\right)!}{n!}}\right|}{n}\right)$$
Let's take the limit
we find
$$\frac{n - 1}{n!}$$
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
$$a_{n} = \frac{n - 1}{n!}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(\frac{\left|{\frac{\left(n - 1\right) \left(n + 1\right)!}{n!}}\right|}{n}\right)$$
Let's take the limit
we find
False
False
The rate of convergence of the power series
The graph
Examples of finding the sum of a series
- The Sum of the Power Series
x^n/n
(x-1)^n
- Factorial
1/2^(n!)
n^2/n!
x^n/n!
k!/(n!*(n+k)!)
- Flint Hills Series
csc(n)^2/n^3
- Basel problem
1/n^2
1/n^4
1/n^6
- Harmonic series
1/n
- Grandi's series
(-1)^n
- Alternating series
(-1)^(n + 1)/n
(n + 2)*(-1)^(n - 1)
(3*n - 1)/(-5)^n
(-1)^(n - 1)*n/(6*n - 5)
- Newton–Mercator series
(-1)^(n + 1)/n*x^n
- Exam the series for convergence
(3*n - 1)/(-5)^n