Results 1 to 2 of 2

Math Help - A function

  1. #1
    Junior Member
    Joined
    May 2009
    Posts
    25

    A function

    Given:
    f(x)=\sqrt{x} and g(x)=x^2-1

    How can I evaluate something like:
    f(g(2)) or g(f(0))

    I seem to get confused whenever they throw a number in the composite. Like I know how to evaluate f(g(x)) but I'm not sure what to do when they place a number in it. :/
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie darthfader's Avatar
    Joined
    Apr 2009
    From
    Philippines
    Posts
    10
    Hi jimmyp

    Evaluating composite functions such as f(g(x)) is just simply evaluating the g(x) first and then taking the value of g(x) as the new 'x' and then evaluate f(x).

    To illustrate what I'm talking about, I'll do the first one for you.

    Given:
    and



    g(2) = 2^2 -1 = 3
    since g(2) = 3 then f(g(2)) = f(3)

    Hence...
    f(3) = \sqrt{3}

    I hope this helps.

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 20
    Last Post: November 27th 2012, 05:28 AM
  2. Replies: 0
    Last Post: October 19th 2011, 04:49 AM
  3. Replies: 4
    Last Post: October 27th 2010, 05:41 AM
  4. Replies: 3
    Last Post: September 14th 2010, 02:46 PM
  5. Replies: 2
    Last Post: September 2nd 2010, 10:28 AM

Search Tags


/mathhelpforum @mathhelpforum