Mister Exam

Other calculators

6/((3*n-2)(3*n+4))
Sum of series/ 6/((3*n-2)(3*n+4))

Sum of series 6/((3*n-2)(3*n+4))


∑
=

The solution

You have entered [src] 
  oo                     
 ___                     
 \  `                    
  \            6         
   )  -------------------
  /   (3*n - 2)*(3*n + 4)
 /__,                    
n = 1
$$\sum_{n=1}^{\infty} \frac{6}{\left(3 n - 2\right) \left(3 n + 4\right)}$$ 
Sum(6/(((3*n - 2)*(3*n + 4))), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{6}{\left(3 n - 2\right) \left(3 n + 4\right)}$$
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
$$a_{n} = \frac{6}{\left(3 n - 2\right) \left(3 n + 4\right)}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(\frac{\left(3 n + 1\right) \left(3 n + 7\right) \left|{\frac{1}{3 n - 2}}\right|}{3 n + 4}\right)$$
Let's take the limit
we find
True

False
The rate of convergence of the power series
The answer [src] 
15*Gamma(10/3)
--------------
28*Gamma(7/3)
$$\frac{15 \Gamma\left(\frac{10}{3}\right)}{28 \Gamma\left(\frac{7}{3}\right)}$$ 
15*gamma(10/3)/(28*gamma(7/3))
Numerical answer [src] 
1.25000000000000000000000000000
1.25000000000000000000000000000
The graph
Sum of series 6/((3*n-2)(3*n+4))

    Examples of finding the sum of a series

    © Mister Exam – Calculator