Positive integers for k: finding limits

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Homework Help Overview

The discussion revolves around finding positive integers k for which the limit of sin(sin(x))/x^k as x approaches 0 exists. Participants are exploring the behavior of this limit for various values of k.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants share their attempts for k = 0, 1, and 2, noting differing outcomes. There are questions about the validity of these results and methods used, including calculator outputs and alternative approaches.

Discussion Status

The discussion is ongoing, with participants questioning the results for k = 1 and k = 2. Some guidance is offered regarding the interpretation of limits and the use of calculators, but no consensus has been reached on the correct approach or answers.

Contextual Notes

There is a noted confusion regarding the definition of positive integers and the implications of limits approaching undefined values. Participants are also considering the behavior of the function as k increases.

chapsticks
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Homework Statement


find the positive integers k for which

lim x->0 sin(sin(x))/x^k

Homework Equations



exists, and then find the value of the limit

The Attempt at a Solution


I did the first three k's

k=0
lim x->0 sin(sin x))/x^0= 0 undefined

k=1
lim x->0 sin(sinx))/x^1= 1

k=2 I might be wrong with this
lim x->0 sin(sinx))/x^2= undefined

k>2 how do I do this one.
lim x-> sin(sinx))/x^k>2=?
 
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0 is not positive.

Regarding k = 2: How did you arrive at your answer for k = 1 ??
 
well I plugged it into my calculator
 
What happens if you multiply and divide sin(x)?
 
I'm not sure.
 
chapsticks said:
I'm not sure.

Do it an see what you recognize
 
well in the table for k=2

it goes from -100 then an error then 99

so it must be for all positive numbers and above should be infinity?
 
chapsticks said:
well I plugged it into my calculator

Are you saying that your calculator says that sin(sin(0))/0 = 1 ?
 
I used a different method.. but that answer sin(sin(0))/0 does not exist right
 
  • #10
chapsticks said:
I used a different method.. but that answer sin(sin(0))/0 does not exist right
Right.

So, I ask again. How did you find the answer when k = 1 ?
 

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