Results 1 to 5 of 5

Math Help - Express in form f(x)=a(x-h)^2+k

  1. #1
    Newbie
    Joined
    Nov 2008
    Posts
    9

    Express in form f(x)=a(x-h)^2+k

    Express f(x)=-2x^2+4x+1 in the form f(x)=a(x-h)^2+k. Find the vertex and the y-intercept and then graph the function.

    I have no idea where to even begin. Anyone?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Rhymes with Orange Chris L T521's Avatar
    Joined
    May 2008
    From
    Chicago, IL
    Posts
    2,844
    Thanks
    3
    Quote Originally Posted by ZE2001 View Post
    Express f(x)=-2x^2+4x+1 in the form f(x)=a(x-h)^2+k. Find the vertex and the y-intercept and then graph the function.

    I have no idea where to even begin. Anyone?
    Rewrite it as -2(x^2-2x)+1, then complete the square on -2(x^2-2x)

    Can you try to take it from here?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Nov 2008
    Posts
    9
    Quote Originally Posted by Chris L T521 View Post
    Rewrite it as -2(x^2-2x)+1, then complete the square on -2(x^2-2x)

    Can you try to take it from here?
    Okay here's what I came up with:

    f(x)=(x-1)^2-3/2
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Nov 2008
    From
    France
    Posts
    1,458
    Quote Originally Posted by ZE2001 View Post
    Okay here's what I came up with:

    f(x)=(x-1)^2-3/2
    Nearly
    You just forgot -2 factor
    f(x)=-2[(x-1)^2-3/2]
    f(x)=-2(x-1)+3
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Nov 2008
    Posts
    9
    Quote Originally Posted by running-gag View Post
    Nearly
    You just forgot -2 factor
    f(x)=-2[(x-1)^2-3/2]
    f(x)=-2(x-1)+3
    Thank you!
    Last edited by ZE2001; November 29th 2008 at 01:22 PM. Reason: nevermind!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Express f(x) in the form (x-a)g(x)
    Posted in the Algebra Forum
    Replies: 4
    Last Post: September 12th 2011, 07:16 PM
  2. Express the eq in a+ib form
    Posted in the Calculus Forum
    Replies: 10
    Last Post: January 6th 2010, 02:07 AM
  3. express in simplest form
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 21st 2009, 01:30 PM
  4. express in simplest form
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 18th 2009, 02:13 PM
  5. Express in standard form!!
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: May 17th 2008, 10:08 AM

Search Tags


/mathhelpforum @mathhelpforum