Results 1 to 3 of 3

Math Help - finding the limit

  1. #1
    Member
    Joined
    Jan 2009
    Posts
    91

    finding the limit

    what is the limit limit as x-> infinity of
    (sin x) / sqrt(x)



    i know lim (sin x)/x = 1
    but how do i find the one above???
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hello,
    Quote Originally Posted by razorfever View Post
    what is the limit limit as x-> infinity of
    (sin x) / sqrt(x)



    i know lim (sin x)/x = 1
    but how do i find the one above???
    Note that for a positive x, x=\sqrt{x} \sqrt{x}

    hence \sqrt{x}=\frac{x}{\sqrt{x}}


    your limit is thus \frac{\sin(x)}{x} \cdot \sqrt{x}
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,602
    Thanks
    1421
    Quote Originally Posted by razorfever View Post
    what is the limit limit as x-> infinity of
    (sin x) / sqrt(x)



    i know lim (sin x)/x = 1
    but how do i find the one above???
    I hope you don't know that! sin(x)/x goes to 1 as x goes to 0 but your limit is for x going to infinity. You know that sin(x) is never larger than 1 nor less than -1: \frac{-1}{x}\le\frac{sin x}{x}\le\frac{1}{x}. Now, what happens to those end terms as x goes to infinity?

    Moo's hint would be relevant if the limit were as x goes to 0. I think you mislead him!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Finding the limit
    Posted in the Calculus Forum
    Replies: 4
    Last Post: October 11th 2011, 07:50 AM
  2. Finding limit of this function, using Limit rules
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: February 27th 2011, 01:12 PM
  3. [SOLVED] Finding f(x) and g(x) - limit
    Posted in the Calculus Forum
    Replies: 7
    Last Post: December 18th 2010, 04:32 AM
  4. Finding a limit. Finding Maclaurin series.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: May 18th 2010, 10:04 PM
  5. help finding the following limit:
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 15th 2008, 09:25 PM

Search Tags


/mathhelpforum @mathhelpforum