What is the partial sum of the series?

In summary, the partial sum of a series is the sum of a finite number of terms in the series and is used to approximate the total sum of an infinite series. It is calculated by adding up the terms in the series up to a given number of terms. The significance of the partial sum is that it helps determine if the series converges or diverges. Additionally, the partial sum can be used to determine the convergence of an infinite series, with methods such as the ratio test or the comparison test. There are also specific methods for finding the partial sum, such as using formulas for geometric or arithmetic series.
  • #1
Feynmanfan
129
0
Hello everybody!

I'm having some trouble with series. My calculus teacher asked us to find the partial sum of

Sigma from 1 to n [n^-(1 + 1/n)]

It is obvious that the series diverges when trying to find the infinite sum. However, is it possible to find an expression dependant of n of the partial sum? I don't know where to start from
 
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  • #2
1/(n*n^1/n) ... how does that go on the tex thing? I couldn't get it to work...
 
Last edited:
  • #3
.

The partial sum of a series is the sum of a certain number of terms in the series, rather than the sum of all infinite terms. In this case, the partial sum of the series would be the sum of the first n terms, where n is a positive integer. To find the partial sum of this specific series, you can use the formula for the sum of a geometric series, which is Sn = a(1-r^n)/(1-r), where a is the first term and r is the common ratio. In this case, a = 1 and r = 1/n. So the partial sum would be Sn = 1(1-(1/n)^n)/(1-(1/n)). Simplifying this expression would give you the partial sum as n approaches infinity. However, since this series diverges, the partial sum would also approach infinity as n approaches infinity. Therefore, there is no finite expression for the partial sum of this series.
 

1. What is the definition of "Partial sum of a series"?

The partial sum of a series is the sum of a finite number of terms in the series. It is used to approximate the total sum of an infinite series.

2. How is the partial sum of a series calculated?

The partial sum of a series is calculated by adding up the terms in the series starting from the first term up to a given number of terms.

3. What is the significance of the partial sum of a series?

The partial sum of a series is used to approximate the total sum of an infinite series. It helps us to understand the behavior of a series and determine if it converges or diverges.

4. Can the partial sum of a series be used to determine the convergence of an infinite series?

Yes, the partial sum of a series can be used to determine the convergence of an infinite series. If the partial sums approach a finite limit as the number of terms increases, then the series is said to converge. If the partial sums do not approach a finite limit, then the series is said to diverge.

5. Are there any specific methods for finding the partial sum of a series?

Yes, there are various methods for finding the partial sum of a series, such as using the formula for the sum of a geometric series or using the partial sum formula for arithmetic or geometric series. There are also more advanced methods, such as the ratio test or the comparison test, for determining the convergence of an infinite series.

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