Results 1 to 5 of 5

Math Help - use sequences to guess which points of f has a limit

  1. #1
    Member
    Joined
    Feb 2010
    Posts
    146

    use sequences to guess which points of f has a limit

    Sorry this is the last question i was confused with on my new review sheet. However I'm pretty sure I wont figure this answer out as soon as i post (sorry about that) so im sure this time i need help

    Define f : R->R as follows:

    f(x)= 8x if x is a rational number
    f(x)= 2 x^2+8 if x is an irrational number.

    use sequences to guess at which points f has a limit, then use \epsilon's and delta's to justify your conclusions.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Drexel28's Avatar
    Joined
    Nov 2009
    From
    Berkeley, California
    Posts
    4,563
    Thanks
    21
    Quote Originally Posted by tn11631 View Post
    Sorry this is the last question i was confused with on my new review sheet. However I'm pretty sure I wont figure this answer out as soon as i post (sorry about that) so im sure this time i need help

    Define f : R->R as follows:

    f(x)= 8x if x is a rational number
    f(x)= 2 x^2+8 if x is an irrational number.

    use sequences to guess at which points f has a limit, then use \epsilon's and delta's to justify your conclusions.
    Consider sequences of rational and irrational points respectively.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Feb 2010
    Posts
    146
    Quote Originally Posted by Drexel28 View Post
    Consider sequences of rational and irrational points respectively.
    idk what it is, but im drawing a blank on this one. Like 8x as x->1/2 , and 2x^2+8 x-> sqrt(2)?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor Drexel28's Avatar
    Joined
    Nov 2009
    From
    Berkeley, California
    Posts
    4,563
    Thanks
    21
    Quote Originally Posted by tn11631 View Post
    idk what it is, but im drawing a blank on this one. Like 8x as x->1/2 , and 2x^2+8 x-> sqrt(2)?
    I don't see where you used sequences there.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Feb 2010
    Posts
    146
    Quote Originally Posted by Drexel28 View Post
    I don't see where you used sequences there.
    ah i'm confusing myself more..lol
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Limit of 2 sequences
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 4th 2009, 01:34 PM
  2. Guess the Limit of....
    Posted in the Calculus Forum
    Replies: 1
    Last Post: September 24th 2009, 03:36 PM
  3. Limit Theorems, Sequences
    Posted in the Differential Geometry Forum
    Replies: 6
    Last Post: March 30th 2009, 05:30 PM
  4. Replies: 3
    Last Post: January 11th 2009, 11:49 AM
  5. Limit of Sequences
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 1st 2008, 11:23 AM

Search Tags


/mathhelpforum @mathhelpforum