Mister Exam

Other calculators


sqrt(3n+4)-sqrt(3n+1)

Sum of series sqrt(3n+4)-sqrt(3n+1)



=

The solution

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

False
The rate of convergence of the power series
The answer [src]
oo
$$\infty$$
oo
The graph
Sum of series sqrt(3n+4)-sqrt(3n+1)

    Examples of finding the sum of a series