Thursday, December 15, 2011

How do I find the limit of this as it approaches infinity?

I don't understand how to find the limit of the following:


(2n^2-3n-11)/(6n^2)


as n approaches infinity. I understand I should factor 1/6 out of it and that the answer is 1/3, but I don't understand the steps to get there.|||I 'll try to solve it with L' Hospital rule,





L = lim (2n虏 - 3n - 11)/(6n虏)


......n 鈫?鈭?br>




both numerator and enumerator derive with respect to n





L = lim (4n - 3)/(12n)


......n 鈫?鈭?br>




L = lim 4/12


......n 鈫?鈭?br>




L = 1/3





- - - - - - - - - - - -- - - - - - - - - - - - - - -- - - - - - - - - - - - - - -- - - 鉁?br>




Ok, I'll show you another method to solve this problem,





L = lim (2n虏 - 3n - 11)/(6n虏)


......n 鈫?鈭?br>




divided numerator and enumerator with n虏





L = lim (2 - 3/n - 11/n虏)/6


......n 鈫?鈭?br>




L = (2 - 0 - 0)/6 = 1/3|||(2n^2-3n-11)/(6n^2) = 2n^2 / 6n^2 -3n/6n^2 - 11/6n^2


= 1/3 - 1/2n - 11/6n^2


as n approaches infinity, both 1/2n and 11/6n^2 near zero, which means your limit is 1/3

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