Results 1 to 5 of 5

Math Help - function composition

  1. #1
    Member
    Joined
    Jun 2006
    Posts
    165

    Question algebra and trigonometry with analytic geometry problem

    Given f(x)=5x+7 and g(x)=x^2+7, find (g 0 f)(x). I think it is (g 0 f)(x) = (5x)^2+14, gut not sue thanks for any help given.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by kwtolley
    Given f(x)=5x+7 and g(x)=x^2+7, find (g 0 f)(x). I think it is (g 0 f)(x) = (5x)^2+14, gut not sue thanks for any help given.
    (g \circ f)(x)=g(f(x))=g(5x+7)=(5x+7)^2+7

    RonL
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jun 2006
    Posts
    165

    answer

    so 5x^2+7 is the answer. thanks again.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by kwtolley
    so 5x^2+7 is the answer. thanks again.
    No.

    <br />
(g \circ f)(x)=g(f(x))=g(5x+7)=(5x+7)^2+7 =25x^2+70x+56<br />

    RonL
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,899
    Thanks
    327
    Awards
    1
    Quote Originally Posted by kwtolley
    so 5x^2+7 is the answer. thanks again.
    kwtolley, just a thought. You seem to know the method to do these problems, but you are consistently getting them wrong due to minor errors. My thought it that you are simply trying to do them too fast. If you are not doing so already I would suggest you write down each step of the problem as you are doing it.

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Function Composition.
    Posted in the Algebra Forum
    Replies: 2
    Last Post: December 8th 2011, 12:04 PM
  2. function composition
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: February 27th 2009, 10:15 AM
  3. Composition of a function
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: October 17th 2008, 01:20 PM
  4. Function Composition
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: September 14th 2008, 12:28 PM
  5. Function Composition
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: February 12th 2008, 12:51 PM

Search Tags


/mathhelpforum @mathhelpforum