Positive integers for k: finding limits

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SUMMARY

The discussion focuses on determining the positive integers k for which the limit lim x->0 sin(sin(x))/x^k exists. It is established that for k=0, the limit is undefined; for k=1, the limit equals 1; and for k=2, the limit is also undefined. Participants express confusion regarding the behavior of the limit for k greater than 2, suggesting that it approaches infinity. The conversation emphasizes the importance of using calculators and alternative methods to analyze the limits effectively.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with the sine function and its properties
  • Basic knowledge of L'Hôpital's Rule for evaluating indeterminate forms
  • Experience with using calculators for mathematical analysis
NEXT STEPS
  • Explore L'Hôpital's Rule for evaluating limits involving indeterminate forms
  • Study the Taylor series expansion of the sine function for better limit evaluation
  • Investigate the behavior of limits as k approaches infinity
  • Practice solving similar limit problems involving trigonometric functions
USEFUL FOR

Students studying calculus, mathematics educators, and anyone interested in advanced limit evaluation techniques.

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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