Mister Exam
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- 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:
-
((-1)^(n+1))/n
-
(1+1/n)^n
-
sin(sin(n)/n^(1/3))
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3/(8^(n-1))
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Identical expressions
- three /(eight ^(n- one))
- 3 divide by (8 to the power of (n minus 1))
- three divide by (eight to the power of (n minus one))
- 3/(8(n-1))
- 3/8n-1
- 3/8^n-1
- 3 divide by (8^(n-1))
-
Similar expressions
- 3/(8^(n+1))
Sum of series 3/(8^(n-1))
The solution
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oo ____ \ ` \ 3 \ ------ / n - 1 / 8 /___, n = 1
$$\sum_{n=1}^{\infty} \frac{3}{8^{n - 1}}$$
Sum(3/8^(n - 1), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{3}{8^{n - 1}}$$
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
$$a_{n} = 3 \cdot 8^{1 - n}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(8^{n} 8^{1 - n}\right)$$
Let's take the limit
we find
$$\frac{3}{8^{n - 1}}$$
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
$$a_{n} = 3 \cdot 8^{1 - n}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(8^{n} 8^{1 - n}\right)$$
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