Limit of e^(-2x) * cosx as x-> ∞

  • Thread starter TsAmE
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  • #1
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Problem statement: Find the limit of e^(-2x) * cosx as x-> ∞

Attempt at solution: I tried to say that the limit of e^(-2x) as x-> ∞ is 0, and the limit of cosx doesn't exist since it oscillates between -1 and 1 therefore the overall answer is that it doesn't exist. I was wrong however and the right answer was 0. Could someone please help?
 

Answers and Replies

  • #2
lanedance
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limit of cos(x) doesn't exist but can you put bounds on its absolute value?

whats the limit of e^(-2x) times the upper bound?
 
  • #3
D H
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Try applying the squeeze theorem.
 

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