Does f(x) Approach Zero as x Approaches Infinity?

  • Thread starter Thread starter Math_Frank
  • Start date Start date
  • Tags Tags
    Integral
Click For Summary

Homework Help Overview

The discussion revolves around the behavior of a function \( f(x) \) as \( x \) approaches infinity, particularly in the context of an integral involving \( f(x) \). Participants are exploring the conditions under which \( f(x) \) approaches zero and the implications of this behavior.

Discussion Character

  • Conceptual clarification, Assumption checking, Exploratory

Approaches and Questions Raised

  • Participants are questioning the meaning and implications of the integral and the conditions for \( f(x) \) approaching zero. There are attempts to clarify the relationship between the integral and the limit of \( f(x) \) as \( x \) approaches infinity.

Discussion Status

The discussion is ongoing, with participants seeking clarification on the definitions and conditions involved. Some have offered guidance on the need to demonstrate both existence and convergence of the limit, while others are still trying to understand the original question and its context.

Contextual Notes

There is some confusion regarding the notation and the specific limits being discussed, particularly the introduction of \( n \) and its relevance to the limit of \( f(x) \). Participants are also addressing the need for clearer definitions of convergence and limits in this context.

Math_Frank
Messages
27
Reaction score
0

Homework Statement



Given the odd integral

\int_{a}^{b} f(x) dx How do I prove that

f(x) -> 0 for x \to \infty??

The Attempt at a Solution



Is it? For the above to be true, then there exist an \epsilon > 0 such that

|\int_{a}^{b} f(x) dx-0| \leq \epsilon?

I am stuck here!

Am I going the right way?

Sincerely
Frank
 
Physics news on Phys.org
What you've written doesn't really make sense. What is this question from and about?
 
NateTG said:
What you've written doesn't really make sense. What is this question from and about?

The Question is

Given the integeral

f(t) = \int_{t}^{2t} e^{-x^2} dx then prove that if f(x) \to 0 then

n \to \infty

Isn't that convergens or it simply existence of the limit?
 
Math_Frank said:
The Question is

Given the integeral

f(t) = \int_{t}^{2t} e^{-x^2} dx then prove that if f(x) \to 0 then

n \to \infty

Isn't that convergens or it simply existence of the limit?

Where does n come from?

Do you mean "\lim_{x \rightarrow \infty} f(x)=0" when you write "f(x) \to 0"
 
NateTG said:
Where does n come from?

Do you mean "\lim_{x \rightarrow \infty} f(x)=0" when you write "f(x) \to 0"

Yes.
 
You need to show both existence and convergence of the limit.
 

Similar threads

Replies
6
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
4
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 14 ·
Replies
14
Views
2K
Replies
2
Views
1K