August 21st, 2010, 01:15 AM  #1 
Senior Member Joined: Aug 2010 Posts: 109 Thanks: 0  find the limit 
August 21st, 2010, 02:36 AM  #2 
Member Joined: Jul 2010 Posts: 95 Thanks: 0  Re: find the limit
I would do it like that would be something like then and then but I guess I am completely wrong 
August 21st, 2010, 01:13 PM  #3 
Member Joined: Aug 2010 Posts: 49 Thanks: 0  Re: find the limit
you are completely wrong! Since (because the cosine function is less than 1 for every ) the limit is between 0 and 1. Your application of rules for limits (and mathematics) is wrong  but nevertheless, I am thinking about the right solution. It will be 1... and I hope someone is faster, since I forgot a lot since studying physics. Regards, Jens 
August 21st, 2010, 01:13 PM  #4 
Global Moderator Joined: May 2007 Posts: 6,511 Thanks: 585  Re: find the limit
Let T = (cosx)^1/x^2 = exp[ln(cosx)/x^2]. As x >0, cosx ~ 1  x^2/2, so ln(cosx) ~  x^2/2, therefore T ~ exp(1/2). 
August 21st, 2010, 04:44 PM  #5 
Newbie Joined: Aug 2010 Posts: 17 Thanks: 0  Re: find the limit
It is my first time, and I worked on the answer, and It is: 1/Sqrt[e]. I hope it is the Right answer. Let me know if I am wrong. 
August 21st, 2010, 05:58 PM  #6 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,807 Thanks: 1045 Math Focus: Elementary mathematics and beyond  Re: find the limit l'Hopital's rule: and again l'Hopital's: 
August 21st, 2010, 06:00 PM  #7 
Member Joined: Aug 2010 Posts: 49 Thanks: 0  Re: find the limit
right! Not a prove but indeed the right way to prove it, I guess. Sorry for the 1 posted.

August 21st, 2010, 06:08 PM  #8 
Member Joined: Aug 2010 Posts: 49 Thanks: 0  Re: find the limit
my posting was with respect to mathman, l'Hospital is a perfect hit.


Tags 
find, limit 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Find the limit  Shamieh  Calculus  4  October 24th, 2013 12:38 AM 
Find a so that the limit is 1/4  chrishaig  Calculus  2  June 27th, 2012 08:59 AM 
How to find a limit  Vasily  Calculus  4  June 5th, 2012 02:20 PM 
Find the limit  Farcheeza  Calculus  1  March 3rd, 2010 05:57 PM 
How do you find a limit?  Wolf  Calculus  7  April 16th, 2009 12:21 PM 