Proving Limit at Infinity: n^(1/n) = 1

In summary, to prove the limit at infinity of n^(1/n) is equal to 1, we use the definition of a limit, assume the existence of a positive number ε, simplify the expression using logarithms and exponents, and choose a value for n that satisfies the definition. A limit at infinity is the value a function approaches as the input variable increases without bound. The limit at infinity of n^(1/n) is equal to 1 because as n gets larger, the value of n^(1/n) gets closer to 1. Proving this limit is significant as it helps us understand the behavior of the function and make predictions for large values of n. Other methods to prove this limit include using L'Hospital's
  • #1
IniquiTrance
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Homework Statement



How can I prove that:

[tex]\lim_{n \rightarrow \infty} n^{\frac{1}{n}}=1[/tex]

Isn't [tex]\infty^{0}[/tex] indeterminate?
Thanks!


Homework Equations





The Attempt at a Solution

 
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  • #2
Yes, it is indeterminant. That's not the end of the story. Indeterminant just means you don't know what the limit is yet. Take the log. Can you prove (1/n)*log(n) approaches 0?
 
  • #3
That becomes [tex]0*\infty[/tex], isn't that indeterminate as well?
 
  • #4
Can't you use L'Hopital's rule?
 
  • #5
Right. Thanks guys!
 

FAQ: Proving Limit at Infinity: n^(1/n) = 1

1. How do you prove that the limit at infinity of n^(1/n) is equal to 1?

To prove this limit, we use the definition of a limit. We start by assuming that there exists a positive number ε, such that for all values of n greater than a certain value, n^(1/n) will be within ε distance from 1. Then, we use the properties of logarithms and exponents to simplify the expression and find an upper bound for n^(1/n). Finally, we choose a value for n that satisfies the definition of a limit and proves that the limit is indeed equal to 1.

2. Can you explain the concept of a limit at infinity?

A limit at infinity is a mathematical concept used to describe the behavior of a function as the input variable approaches infinity. It is defined as the value that the function approaches as the input variable increases without bound. In other words, it is the value that the function "settles" on as it continues to increase without limit.

3. Why is the limit at infinity of n^(1/n) equal to 1?

The limit at infinity of n^(1/n) is equal to 1 because as n gets larger and larger, the value of n^(1/n) gets closer and closer to 1. This can be seen by graphing the function, as the curve approaches the line y=1 as x approaches infinity. Additionally, by evaluating the limit using the definition, we can see that all the terms in the expression n^(1/n) will eventually become insignificant compared to 1 as n gets larger, resulting in a limit of 1.

4. What is the significance of proving the limit at infinity of n^(1/n) = 1?

Proving the limit at infinity of n^(1/n) = 1 is significant because it helps us understand the behavior of this function as n approaches infinity. This information is important in various fields of study, such as calculus, engineering, and physics. It also allows us to make predictions and approximations for large values of n, which can be useful in real-world applications.

5. Are there any other methods to prove the limit at infinity of n^(1/n) = 1?

Yes, there are other methods to prove this limit. One method is to use the L'Hospital's rule, which states that the limit of a fraction of two functions is equal to the limit of their derivatives. Another method is to use the squeeze theorem, which states that if a function is bounded between two other functions that have the same limit, then the middle function also has the same limit. However, the most common method used to prove this limit is the one described in the first question, using the definition of a limit.

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