Finite Limit Problem: Understanding cosx/x^0 = 1

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Homework Help Overview

The discussion revolves around the limit of the expression cos(x)/x^0 as x approaches 0. Participants are exploring the implications of the expression, particularly the interpretation of 0^0 and its behavior in limits.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the validity of the expression and its limit, particularly focusing on the interpretation of x^0 when x approaches 0. Some are attempting to apply L'Hôpital's rule but are finding it unhelpful. There is also discussion about the nature of limits and the behavior of functions as they approach certain values.

Discussion Status

There is an ongoing exploration of the limit and its implications, with some participants expressing confusion about the nature of 0^0 and its role in the limit. Clarifications have been made regarding the expression, and some participants are beginning to understand the reasoning behind the limit approaching 1.

Contextual Notes

Participants are working under the assumption that x is not equal to 0 in the limit process, which raises questions about the behavior of the expression as it approaches 0. The discussion also highlights a potential typo in the original limit expression that needed clarification.

lukatwo
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Homework Statement



I've read in my textbook, and confirmed via WolframAlpha that lim x->0 (cosx/x^0) =1 , and need an explanation for it. I thought it should be ∞ or something undefined, since 0^0 is undefined.

Homework Equations


The Attempt at a Solution



I tried to use L'Hospitale on the expression, but that led to nowhere. There's no intermediate step between the expression and solution in both textbook, and Wolfram.
 
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lukatwo said:

Homework Statement



I've read in my textbook, and confirmed via WolframAlpha that lim n->0 (cosx/x^0) =1
Typo?
There is no n in your limit expression.

Is this the limit?
$$\lim_{x \to 0} \frac{cos(x)}{x^0} $$
lukatwo said:
, and need an explanation for it. I thought it should be ∞.

Homework Equations





The Attempt at a Solution



I tried to use L'Hospitale on the expression, but that led to nowhere. There's no intermediate step between the expression and solution in both textbook, and Wolfram.
 
It was a typo. Fixed, and yes that is the limit i was referring to!
 
As long as x ≠ 0, x0 = 1, right? So, then, what is ##\lim_{x \to 0} x^0##?
 
From all this my guess will be 1, but still not clear why. Is it because lim x->0 means that x !=0 but rather close to 0? Meaning some infinitesimal number ^0=1? Am i getting that correctly?
 
lukatwo said:
From all this my guess will be 1, but still not clear why. Is it because lim x->0 means that x !=0 but rather close to 0? Meaning some infinitesimal number ^0=1? Am i getting that correctly?
Yes to both questions. The graph of y = x0 is a horizontal line with a hole at (0, 1).
 
I understand now! Thank you very much for your help!
 

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