Limsup, liminf simple question

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In summary, limsup and liminf are mathematical concepts that represent the limit superior and limit inferior, respectively, of a sequence of numbers. They are calculated by taking the supremum and infimum of the set of all limit points of the sequence. The main difference between limsup and liminf is how they approach the limit of a sequence, with limsup considering the largest limit point and liminf considering the smallest limit point. These concepts are important in mathematics as they help describe the behavior of a sequence as it approaches infinity and are used in the definition of other important concepts such as continuity and convergence. In real life, they are used to model and analyze various phenomena and are also applicable in engineering and physics to study the behavior of systems and
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St41n
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Is [tex]\limsup\limits_{n\in\mathbb{N}} x_n[/tex] any different than [tex]\limsup\limits_{n\to\infty} x_n[/tex] ?
 
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  • #2
The limsup is a limit, so the notation on the left doesn't really have any meaning and the notation on the right is correct. You use something like what you have on the left for just the sup, i.e. [tex]\sup_{n\in\mathbb{N}}[/tex] of some set.
 
  • #3
that makes sense, thanks
 

Related to Limsup, liminf simple question

What is limsup and liminf?

Limsup and liminf are mathematical concepts that represent the limit superior and limit inferior, respectively, of a sequence of numbers. They are used to describe the behavior of a sequence as it approaches infinity.

How are limsup and liminf calculated?

The limsup of a sequence is the largest limit point that the sequence can have, while the liminf is the smallest limit point. They are calculated by taking the supremum (the least upper bound) and infimum (the greatest lower bound) of the set of all limit points of the sequence.

What is the difference between limsup and liminf?

The main difference between limsup and liminf is how they approach the limit of a sequence. Limsup considers the largest limit point, while liminf considers the smallest limit point. Additionally, limsup always exists, while liminf may not exist.

What is the importance of limsup and liminf in mathematics?

Limsup and liminf are important in mathematics because they help describe the behavior of a sequence as it approaches infinity. They are also used in the definition of other important concepts such as continuity and convergence of a sequence.

How are limsup and liminf used in real life?

Limsup and liminf are used in real life to model and analyze various phenomena, such as stock market trends, weather patterns, and population growth. They are also used in engineering and physics to study the behavior of systems and predict future outcomes.

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