Find the formula to express the infinite series....

In summary, an infinite series is a sum of an infinite number of terms that continue indefinitely. Finding the formula for an infinite series is important because it allows us to calculate the sum and understand the behavior of the series. The process for finding the formula involves identifying patterns and using mathematical techniques. There are different types of infinite series with specific formulas for finding the sum. However, it is not always possible to find the formula for an infinite series, in which case other methods may be used.
  • #1
maxhersch
21
0
The problem is to find the general term ##a_n## (not the partial sum) of the infinite series with a starting point n=1

$$a_n = \frac {8} {1^2 + 1} + \frac {1} {2^2 + 1} + \frac {8} {3^2 + 1} + \frac {1} {4^2 + 1} + \text {...}$$

The denominator is easy, just ##n^2 + 1## but I can't think of any way to get the numerator to alternate between 8 and 1.
 
Physics news on Phys.org
  • #2
##4.5 + 3.5(-1)^{n+1}##
 
  • Like
Likes maxhersch
  • #3
Never mind I figured it out $$a_n = \frac {9 - 7 \{ -1 \} ^n} {2 \{ 1 + n^2 \}}$$
 

1. What is an infinite series?

An infinite series is a sum of an infinite number of terms. Each term in the series is added to the previous term to create a sequence that continues indefinitely.

2. Why is finding the formula for an infinite series important?

Finding the formula for an infinite series allows us to calculate the sum of an infinite number of terms, which is useful in many areas of mathematics and science. It also helps us understand the behavior and patterns of the series.

3. What is the process for finding the formula for an infinite series?

The process for finding the formula for an infinite series involves identifying a pattern in the terms of the series, then using mathematical techniques such as algebra and calculus to derive a general formula that can be used to calculate the sum of any number of terms in the series.

4. Are there different types of infinite series?

Yes, there are different types of infinite series such as arithmetic series, geometric series, and power series. Each type has its own specific formula for finding the sum of the series.

5. Is it always possible to find the formula for an infinite series?

No, it is not always possible to find the formula for an infinite series. Some series may not have a pattern or a general formula that can be derived. In these cases, other methods such as numerical approximations may be used to calculate the sum of the series.

Similar threads

Replies
2
Views
1K
Replies
6
Views
646
  • Calculus
Replies
4
Views
1K
Replies
7
Views
1K
Replies
2
Views
858
  • General Math
Replies
7
Views
1K
  • Calculus
Replies
12
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
231
Replies
1
Views
907
Replies
2
Views
762
Back
Top