Does the Continued Product of Fractions Converge to Zero?

In summary, the continued product of fractions 1/2 x 2/3 x 3/4 x...x (n-1)/n converges to zero and this can be verified by taking the logarithm of the product and using known methods to determine the convergence of the corresponding infinite sum. The result is that the infinite product converges if and only if the infinite sum converges, and if the sum converges to M, then the product converges to e^M.
  • #1
SW VandeCarr
2,199
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Does the continued product of fractions 1/2 x 2/3 x 3/4 x...x (n-1)/n converge? If so, what does it converge to?
 
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  • #2
The easiest way to verify is this:

1. Take the logarithm of your infinite product. This produces an infinite sum (series).

2. Use any of the well-known methods to determine if the infinite sum converges.

3. The infinite product converges if and only if the corresponding infinite sum converges.

4. If the infinite product converges, and the infinite sum converges to M, then the infinite product converges to e^M.
 
  • #3
Thanks Ben Niedoff

The sum of the logarithms appears to diverge to negative infinity (-inf) but increasingly slowly. Therefore e^-inf which I took to be the limit (0) of the continued product, but the increasing slowness of convergence gave me second thoughts.
 
  • #4
I think the product you gave actually converges to zero. I think it's telescoping. As was suggested, this should become more apparent after taking the logarithm.
 
  • #5
AUMathTutor said:
I think the product you gave actually converges to zero. I think it's telescoping. As was suggested, this should become more apparent after taking the logarithm.

ln((n-1)/n)= ln(n-1) - ln(n) Yes, I agree. Thanks.
 

FAQ: Does the Continued Product of Fractions Converge to Zero?

What is a continued product of fractions?

A continued product of fractions is a mathematical expression made up of multiple fractions multiplied together, where the numerator of each subsequent fraction is equal to the denominator of the previous fraction. This type of expression is also known as an infinite product, as it can continue infinitely.

How do you find the value of a continued product of fractions?

To find the value of a continued product of fractions, you can use the formula:
a1 * a2 * a3 * ... = a1 / (1 - r)
where a1 is the first term and r is the common ratio between each term. Alternatively, you can also use a calculator or a computer program to calculate the value.

What is the connection between continued product of fractions and geometric series?

A geometric series is a series of terms where each term is multiplied by a constant ratio. Similarly, a continued product of fractions is a series of fractions where each fraction is multiplied by the same constant. Therefore, continued product of fractions and geometric series are closely related and can be used to find the sum of an infinite series.

What are some real-life applications of continued product of fractions?

Continued product of fractions have various applications in economics, physics, and engineering. For example, they can be used to calculate compound interest, population growth, and the rate of radioactive decay. They are also used in the study of fractals and in the construction of musical scales.

Are there any limitations to using continued product of fractions?

Yes, there are limitations to using continued product of fractions. Since they are infinite expressions, they can be difficult to calculate and can only be used for certain types of problems. Additionally, they may not always converge to a finite value, making them unsuitable for some mathematical applications. Therefore, it is important to carefully consider the use of continued product of fractions in problem-solving and to use other methods when necessary.

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