Is the Limit of an Irrational Sequence Also Irrational?

  • Thread starter Physicist97
  • Start date
  • Tags
    Sequence
In summary, the conversation discusses whether the irrationality of a sequence's limit can be proved through induction if the sequence and its next term are both irrational. The question also asks if there is a theorem that supports this idea. An example of an irrational sequence is given as ##\frac{\pi}{n}+1## for ##n \in \mathbb N, n\neq 0##.
  • #1
Physicist97
31
4
Hello! So let's say that you have a sequence ##a{_n}## and the limit as ##n->{\infty}## gives the finite number ##b## not equal to zero. If ##a{_n}## is known to be irrational, and ##a{_n}{_+}{_1}## can be shown to be irrational, does it follow by induction that ##b## is irrational? Is there any theorem that states something equivalent to this, or is this not true for all cases? Thank you!
 
Mathematics news on Phys.org
  • #2
Physicist97 said:
Hello! So let's say that you have a sequence ##a{_n}## and the limit as ##n->{\infty}## gives the finite number ##b## not equal to zero. If ##a{_n}## is known to be irrational, and ##a{_n}{_+}{_1}## can be shown to be irrational, does it follow by induction that ##b## is irrational? Is there any theorem that states something equivalent to this, or is this not true for all cases? Thank you!
Hint ##\frac{\pi}{n}+1## is irrational (for ##n \in \mathbb N, n\neq 0##).
 
  • Like
Likes Physicist97, davidmoore63@y and pbuk

FAQ: Is the Limit of an Irrational Sequence Also Irrational?

What is the meaning of rationality of a sequence?

The rationality of a sequence refers to the pattern or logic behind the numbers in a sequence. It describes how the numbers are related to each other and how they can be predicted or calculated.

How do you determine if a sequence is rational?

A sequence is considered rational if there is a clear and consistent pattern in the numbers, and if the numbers can be expressed as a ratio of two integers. This means that the numbers can be written in the form of a/b, where a and b are whole numbers.

What are some examples of rational sequences?

Some common examples of rational sequences include arithmetic sequences (where the difference between consecutive terms is constant), geometric sequences (where the ratio between consecutive terms is constant), and Fibonacci sequences (where each term is the sum of the two previous terms).

How does rationality of a sequence relate to real-life situations?

Rational sequences can be found in many real-life situations, such as in financial markets, scientific experiments, and natural phenomena. They can be used to make predictions and calculations, and to understand patterns and relationships in data.

Can a sequence be both rational and irrational?

No, a sequence can only be either rational or irrational, not both. If a sequence has a clear and consistent pattern, it is considered rational. If there is no discernible pattern or logic behind the numbers, it is considered irrational.

Similar threads

Replies
28
Views
3K
Replies
1
Views
2K
Replies
5
Views
2K
Replies
3
Views
2K
Replies
5
Views
2K
Replies
6
Views
2K
Back
Top