Results 1 to 2 of 2

Math Help - problem into graphing form

  1. #1
    Newbie
    Joined
    Jun 2008
    Posts
    21

    problem into graphing form

    express y+2x^2 -5x +1=0 in the form y=A(x-h)^2+k ....... so am I suppose to complete the square can someone please show the steps
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,909
    Thanks
    773
    Hello, cruxkitty!

    There are a number of ways . . . Here's one of them.


    Express y+2x^2 -5x +1\:=\:0 in the form:  y\:=\:a(x-h)^2+k
    We have: . y +1\;=\;-2x^2 + 5x

    Divide by -2: . -\frac{1}{2}\,y -\frac{1}{2} \;=\;x^2 - \frac{5}{2}x

    Complete the square: . -\frac{1}{2}\,y + \frac{1}{2} + {\color{blue}\frac{25}{16}} \;=\;x^2 - \frac{5}{2}x + {\color{blue}\frac{25}{16}}

    . . and we have: . -\frac{1}{2}\,y + \frac{17}{16} \;=\;\left(x-\frac{5}{4}\right)^2 \quad\Rightarrow\quad -\frac{1}{2}\,y \;=\;\left(x - \frac{5}{4}\right)^2 - \frac{17}{16}


    Multiply by -2: . \boxed{y \;=\;-2\left(x - \frac{5}{4}\right)^2 + \frac{17}{8}}

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. graphing problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 19th 2010, 06:37 AM
  2. Confusion! Graphing a Parabola in Standard Form
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: September 15th 2009, 01:42 PM
  3. graphing problem
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: September 7th 2009, 07:46 PM
  4. Standard form & Graphing
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: January 25th 2009, 08:49 AM
  5. Replies: 1
    Last Post: December 4th 2008, 08:51 PM

Search Tags


/mathhelpforum @mathhelpforum