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(sin(n)/(n))-((sin(n+1))/(n+1))

Sum of series (sin(n)/(n))-((sin(n+1))/(n+1))



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The solution

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  oo                       
 ___                       
 \  `                      
  \   /sin(n)   sin(n + 1)\
   )  |------ - ----------|
  /   \  n        n + 1   /
 /__,                      
n = 1                      
$$\sum_{n=1}^{\infty} \left(- \frac{\sin{\left(n + 1 \right)}}{n + 1} + \frac{\sin{\left(n \right)}}{n}\right)$$
Sum(sin(n)/n - sin(n + 1)/(n + 1), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$- \frac{\sin{\left(n + 1 \right)}}{n + 1} + \frac{\sin{\left(n \right)}}{n}$$
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
$$a_{n} = - \frac{\sin{\left(n + 1 \right)}}{n + 1} + \frac{\sin{\left(n \right)}}{n}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty} \left|{\frac{\frac{\sin{\left(n + 1 \right)}}{n + 1} - \frac{\sin{\left(n \right)}}{n}}{\frac{\sin{\left(n + 2 \right)}}{n + 2} - \frac{\sin{\left(n + 1 \right)}}{n + 1}}}\right|$$
Let's take the limit
we find
$$1 = \lim_{n \to \infty} \left|{\frac{\frac{\sin{\left(n + 1 \right)}}{n + 1} - \frac{\sin{\left(n \right)}}{n}}{\frac{\sin{\left(n + 2 \right)}}{n + 2} - \frac{\sin{\left(n + 1 \right)}}{n + 1}}}\right|$$
False
The rate of convergence of the power series
The answer [src]
sin(1)
$$\sin{\left(1 \right)}$$
sin(1)
The graph
Sum of series (sin(n)/(n))-((sin(n+1))/(n+1))

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