Results 1 to 6 of 6

Math Help - Functions questions

  1. #1
    Member
    Joined
    Jul 2008
    Posts
    212

    Functions questions

    The questions are here: Yfrog Image : yfrog.com/mgmathfuncj sorry it never works when I try to upload an image on mathhelpforum for some reason!

    So, for example is h(17) just h(17) = 17/4 = 4.25? But for this, isn't it not defined as it is not within the set said N --> {0, 1, 2, 3}

    k(5) = 2 x (5)^2 + 1 = 51

    L(6) = 2 x 6 = 12.

    Am I on the right track with these kind of questions or completely lost?
    Last edited by brumby_3; August 3rd 2010 at 06:42 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Banned
    Joined
    Oct 2009
    Posts
    4,261
    Thanks
    2
    Quote Originally Posted by brumby_3 View Post
    The questions are here: Yfrog Image : yfrog.com/mgmathfuncj sorry it never works when I try to upload an image on mathhelpforum for some reason!

    So, for example is h(17) just h(17) = 17/4 = 4.25?


    No, why? When you divide 17 by 4 the residue is 1, since 17=4\cdot4+1 , so h(17)=1...


    But for this, isn't it not defined as it is not within the set said N --> {0, 1, 2, 3}

    k(5) = 2 x (5)^2 + 1 = 51

    L(6) = 2 x 6 = 12.

    Am I on the right track with these kind of questions or completely lost?

    You're right in the last two functions.

    Tonio
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jul 2008
    Posts
    212
    For g(7), do I do g(7+1) = g(8) = 1+ (g(7)/2)
    But then I'm confused lol.

    And also could I get some help with f o h(3), I can't figure it out.

    Thanks!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,517
    Thanks
    769
    For g(7), do I do g(7+1) = g(8) = 1+ (g(7)/2)
    No, you have to represent the argument 7 as n + 1. I.e., g(7) = g(6 + 1) = 1 + g(6) / 2. At this point it may be easier to forget about g(7) and calculate g(6) first. And for that you have to compute g(5), etc.

    By definition, f o h(3) = f(h(3)).
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Jul 2008
    Posts
    212
    For f o h (3), my answer is 1, but for h o f(3), is the answer 1 as well or 3?
    Last edited by brumby_3; August 4th 2010 at 07:40 PM.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,517
    Thanks
    769
    for h o f(3), is the answer 1 as well or 3?
    It is also 1: f(3) = 1 and h(1) = 1. Here the answer is the same because h(n) = n for n < 4, and the composition of f with the identity function does not change f, whether the identity function is applied first or last. In general, however, the order of functions in composition matters. For example, h(f(2)) = 0, but f(h(2)) = 4.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. questions on functions
    Posted in the Algebra Forum
    Replies: 7
    Last Post: August 8th 2011, 05:18 AM
  2. few functions questions
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: July 25th 2010, 01:54 AM
  3. Two questions on functions
    Posted in the Differential Geometry Forum
    Replies: 6
    Last Post: November 13th 2009, 05:32 AM
  4. advanced functions questions
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: March 25th 2009, 06:32 PM
  5. Functions questions
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 15th 2008, 04:42 AM

Search Tags


/mathhelpforum @mathhelpforum