What is the Limit of e^(1/x) as x Approaches 0 and the Direction Matters?

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Homework Help Overview

The discussion revolves around the limit of the function e^(1/x) as x approaches 0, with particular attention to the direction from which x approaches 0. Participants are exploring the implications of approaching from the left versus the right.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the interpretation of limits involving e^(1/x) as x approaches 0, particularly the behavior of the function when approaching from different directions. There is a focus on the mathematical expressions involved and their implications.

Discussion Status

Some participants have identified potential mistakes in the reasoning presented, particularly regarding the behavior of the function as b approaches 0 from below. There is an acknowledgment of the different outcomes based on the direction of approach, with some guidance offered about the behavior of related terms.

Contextual Notes

There is a mention of specific terms and limits that may be causing confusion, such as the behavior of x e^(-x) as x tends to +infinity, which is relevant to the limit being discussed.

Phys12
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1cbf4ac287084491ad5b7ed95f9ed522.jpg

In this solution, in the last 3rd line, I get the first part (-e^-1 - e^-1), however, after the '-' symbol, the person writes (1/b * e^1/b - e^1/b) and takes the limit as b->0. However, shouldn't this give him (inf. * e^inf - e^inf)?

Thanks
(His answer is correct, by the way)
 
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Phys12 said:
1cbf4ac287084491ad5b7ed95f9ed522.jpg

In this solution, in the last 3rd line, I get the first part (-e^-1 - e^-1), however, after the '-' symbol, the person writes (1/b * e^1/b - e^1/b) and takes the limit as b->0. However, shouldn't this give him (inf. * e^inf - e^inf)?

Thanks
(His answer is correct, by the way)
b approaches 0 from below, so 1/b tends to minus infinity. There is a small mistake: the 1 in the (1 . 0 - 0) term. Need to use the fact that x e-x tends to 0 as x tends to +infinity.
 
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haruspex said:
b approaches 0 from below, so 1/b tends to minus infinity. There is a small mistake: the 1 in the (1 . 0 - 0) term. Need to use the fact that x e-x tends to 0 as x tends to +infinity.
Ohk! I didn't notice the fact that we were approaching 0 from the left hand side. Thanks! :)
 
Phys12 said:
Ohk! I didn't notice the fact that we were approaching 0 from the left hand side. Thanks! :)

Right: if you approach 0 from the right the function blows up: ##\lim_{x \to 0+} e^{1/x} = +\infty##.
 

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