Mister Exam

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How to use it?
Sum of series:
cos(n*x)/(n^2+1)
factorial(n+1)/8^(n+1)
(3*x^2-2*x+3)/factorial(x+1)
(3*n-1)/factorial(n)
Identical expressions
(three *n+ one)/(five ^n)
(3 multiply by n plus 1) divide by (5 to the power of n)
(three multiply by n plus one) divide by (five to the power of n)
(3*n+1)/(5n)
3*n+1/5n
(3n+1)/(5^n)
(3n+1)/(5n)
3n+1/5n
3n+1/5^n
(3*n+1) divide by (5^n)
Similar expressions
(3*n-1)/(5^n)

Sum of series/ (3*n+1)/(5^n)

Sum of series (3*n+1)/(5^n)

The solution

You have entered [src]

  oo         
____         
\   `        
 \    3*n + 1
  \   -------
  /       n  
 /       5   
/___,        
n = 1

$$\sum_{n=1}^{\infty} \frac{3 n + 1}{5^{n}}$$

Sum((3*n + 1)/5^n, (n, 1, oo))

The radius of convergence of the power series

Given number:
$$\frac{3 n + 1}{5^{n}}$$
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
$$a_{n} = 3 n + 1$$
and
$$x_{0} = -5$$
,
$$d = -1$$
,
$$c = 0$$
then
$$\frac{1}{R} = \tilde{\infty} \left(-5 + \lim_{n \to \infty}\left(\frac{3 n + 1}{3 n + 4}\right)\right)$$
Let's take the limit
we find

False

$$R = 0$$

The rate of convergence of the power series

The answer [src]

19
--
16

$$\frac{19}{16}$$

19/16

Numerical answer [src]

1.18750000000000000000000000000

1.18750000000000000000000000000

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
```

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How to use it?

Identical expressions

Similar expressions

Sum of series (3*n+1)/(5^n)

The solution

Examples of finding the sum of a series