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Homework Help: Limits -

  1. Oct 27, 2007 #1
    Limits - Please Help!

    I have been set 4 questions, i basically have no idea if the ones i have tried are correct and have no idea how to even start the other 2. Any help would be much appreciated. I have scanned them in (easier than typing i think).

    http://img90.imageshack.us/img90/7247/scan0001dg1.th.jpg [Broken] http://img230.imageshack.us/img230/562/scan0002ql7.th.jpg [Broken]


    I am not asking for the answers just some help to put me on the right path.

    Thanks
     
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Oct 27, 2007 #2
    b)use the rationalization of the numerator.
    [tex] n \left( { \sqrt{1+n^{2}}-n } \right) = \frac{n \left( { 1+n^{2}-n^{2} } \right)}{\sqrt{1+n^{2}}+n} [/tex]
    c)watch the given hint carefully!
    [tex] \left( { \frac{3}{2} } \right)^{2n} < \left( { \frac{2n+1}{n+1} } \right)^{2n} [/tex]
    you'd better prove the given hint by the induction...

    I think the other answers are right in the way you solved.
     
  4. Oct 27, 2007 #3
    thats great, youv been really helpfull, one thing though.. does that mean c) lim xn tends to infinity?
     
  5. Oct 28, 2007 #4
    ........
     
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