How many terms of the series are needed in order to estimate the exact sum within .01

In summary, to estimate the exact sum within .01 for the series ∑ (-1)n/(ln(n+1)), we can use the remainder estimate for the integral test where Rn=s-sn. This involves comparing the error to the first term not included using the theorem for alternating series. The integral can be used in this method, but there may be other approaches as well.
  • #1
kuczmama
11
0

Homework Statement



How many terms of the series

Ʃ (-1)n/(ln(n+1))
n=1
are needed in order to estimate the exact sum within .01

Homework Equations



I know that I need to use the remainder estimate for the integral test where Rn=s-sn

and that ∫ from (n+1) to ∞ of f(x)dx [itex]\leq[/itex] Rn [itex]\leq[/itex] ∫ from (n) to ∞ of f(x)dx



The Attempt at a Solution



I tried to take the integral but I don't know how, and I can't figure out another way to approach the problem
 
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  • #2


I don't think you want to use an integral.

Hint: Don't you have a theorem for alternating series (with certain hypotheses) that compares the error to the first term not included?
 

1. How do you know how many terms of the series are needed to estimate the exact sum within .01?

The number of terms needed to estimate the exact sum within .01 depends on the specific series being evaluated. In general, the more terms you include in the series, the closer your estimate will be to the exact sum. However, there are also mathematical techniques and formulas that can be used to determine the minimum number of terms needed for a given level of accuracy.

2. Can you provide an example of a series where a large number of terms is needed to estimate the exact sum within .01?

One example is the series for pi, which is an infinite series that converges very slowly. It requires a large number of terms (over 10,000) to estimate the exact sum within .01.

3. Is there a way to improve the accuracy of the estimate without adding more terms to the series?

Yes, there are techniques like error estimation and convergence acceleration that can be used to improve the accuracy of the estimate without adding more terms to the series. These methods involve manipulating the terms of the series in a specific way to reduce the error in the final result.

4. Are there any series where a small number of terms is sufficient to estimate the exact sum within .01?

Yes, there are series that converge quickly and only require a small number of terms to estimate the exact sum within .01. One example is the series for the natural logarithm, which converges rapidly and only needs a few terms for a very accurate estimate.

5. How do you determine the accuracy of the estimate for a given number of terms?

The accuracy of the estimate for a given number of terms can be determined by calculating the error, which is the difference between the estimated sum and the exact sum. This error can be compared to the desired level of accuracy (.01 in this case) to determine if more terms are needed to improve the estimate.

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