lim n-> infinity (cos(4*x/(n^.5)))^n

I can plug this into mathematica and get e^-(8*x^2) but I don't know how that answer was obtained...

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- September 22nd 2009, 07:36 AMsomalim n->infinity for cos function
lim n-> infinity (cos(4*x/(n^.5)))^n

I can plug this into mathematica and get e^-(8*x^2) but I don't know how that answer was obtained... - September 22nd 2009, 07:45 AMChris L T521
- September 22nd 2009, 08:08 AMsoma
For L'Hôpital's rule, I derived the top and bottom and got 0/0 again, and the second derivative looks daunting. Can you help me further with this?

- September 22nd 2009, 08:20 AMChris L T521
- September 22nd 2009, 09:11 AMsoma
Perfect! :)

It took me a while to compute those derivatives myself, but I see how it all fits together now. Thanks so much! - September 22nd 2009, 09:12 AMsoma
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