Let f be a function that has a finite limit at infinity. It is true that this alone is not enough to show that its derivative converges to zero at infinity. So I was wondering weather there were any additional conditions for f that could give the desired outcome. I am also aware of Barbalat's Lemma but this requires uniform continuity, a property which in many occasions is not easy to verify. Thank you
If a function has a finite limit at infinity, are there any additional conditions that could imply that its derivative converges to zero?
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calculus
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5If its derivative's limit exists, then it should be zero. – 2012-11-11
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1What Eastsun says sounds right. For an example of a function with limit 0, but the derivative lacks a limit, see $\sin(x^2)/x.$ – 2012-11-11