Does this Series Converge or Diverge, by which test(s)?

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If L < 1, it converges.In summary, the conversation is discussing whether the series Ʃ (2n)!/(n-1)*3^n converges or diverges. The speaker tried using the ratio test and nth-term test, but ended up with an infinite result and was unsure about its convergence. Another person pointed out that if the limit from the ratio test is greater than 1, then the series diverges. The speaker then corrected themselves, stating that they had forgotten that if the limit is less than 1, then the series converges.
  • #1
Alexc475
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Homework Statement



Does The series Ʃ (2n)!/(n-1)*3^n converge or diverge?

(Starts at n=2 to infinity )

Homework Equations





The Attempt at a Solution



I tried the ratio test and nth-term test, and ended up with infinity, I'm not sure about it's convergence.
 
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  • #2
Alexc475 said:

Homework Statement



Does The series Ʃ (2n)!/(n-1)*3^n converge or diverge?

(Starts at n=2 to infinity )

Homework Equations





The Attempt at a Solution



I tried the ratio test and nth-term test, and ended up with infinity, I'm not sure about it's convergence.

If the ratio you get from the ratio test goes to infinity, then the series diverges.
 
  • #3
Dick said:
If the ratio you get from the ratio test goes to infinity, then the series diverges.

Ohh no wonder. Thank you! I forgot that if L>1 (L being the limit) that it converges
 
  • #4
Alexc475 said:
Ohh no wonder. Thank you! I forgot that if L>1 (L being the limit) that it converges
No, if L > 1, it diverges.
 

FAQ: Does this Series Converge or Diverge, by which test(s)?

What is the difference between a convergent and divergent series?

A convergent series is one in which the sum of all the terms in the series approaches a finite number as the number of terms increases. In contrast, a divergent series is one in which the sum of all the terms in the series either approaches infinity or does not approach a finite number.

What is the purpose of determining whether a series converges or diverges?

Determining whether a series converges or diverges is important in understanding the behavior of a given sequence of numbers or values. It can also help in evaluating the accuracy of mathematical models and in making predictions based on the given data.

What is the most commonly used test for determining convergence or divergence of a series?

The most commonly used test for determining convergence or divergence of a series is the Comparison Test. This test involves comparing the given series to a known series with known convergence or divergence properties.

What are some other tests that can be used to determine convergence or divergence of a series?

Other commonly used tests for determining convergence or divergence include the Limit Comparison Test, the Ratio Test, the Root Test, and the Integral Test. Each of these tests has its own conditions and criteria for determining convergence or divergence of a series.

Can a series converge and diverge at the same time?

No, a series cannot converge and diverge at the same time. A series can either converge or diverge, but not both. If a series satisfies the criteria for both convergence and divergence, then it is known as a conditionally convergent series.

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