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Determine whether the following series is convergent or divergent. If it converges, find its value. If it diverges, enter DIV.

1/5 + 1/13 + 1/21 + 1/29 + 1/37 + 1/45 + ...​

User MadRabbit
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1 Answer

4 votes

Final answer:

The common ratio between the terms is 1/8. When the absolute value of the common ratio is less than 1, the series converges. In this case, |1/8| < 1. The given series is convergent and its value is 8/35.

Step-by-step explanation:

To determine whether the given series is convergent or divergent, we can use the concept of an infinite geometric series. The series can be expressed as:

1/5 + 1/13 + 1/21 + 1/29 + 1/37 + 1/45 + ...

The common ratio between the terms is 1/8. When the absolute value of the common ratio is less than 1, the series converges. In this case, |1/8| < 1, so the series converges.

To find its value, we can use the formula for the sum of an infinite geometric series:

Sum = a / (1 - r), where a is the first term and r is the common ratio.

Plugging in the values, we have:

Sum = (1/5) / (1 - 1/8)

Simplifying the expression, we get:

Sum = (8/40) / (7/8) = 64/280 = 8/35

Therefore, the value of the series is 8/35.

User Laurens Rietveld
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