Results 1 to 5 of 5

Math Help - Analytic Geometry- Analyse y^2 + 6y +2x + 1 = 0

  1. #1
    Newbie
    Joined
    Oct 2011
    Posts
    18

    Analytic Geometry- Analyse y^2 + 6y +2x + 1 = 0

    Hello,

    I need help with this problem:

    Analyze the equation y^2 + 6y +2x + 1 = 0

    By analyze the problem means to find the center, foci, and vertices.

    I do not know how to get this equation into standard form. (I believe that is the goal.)

    Please help me.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,656
    Thanks
    1479

    Re: Analytic Geometry- Analyze the equation

    Quote Originally Posted by dazedandmathfused View Post
    Hello,

    I need help with this problem:

    Analyze the equation y^2 + 6y +2x + 1 = 0

    By analyze the problem means to find the center, foci, and vertices.

    I do not know how to get this equation into standard form. (I believe that is the goal.)

    Please help me.
    \displaystyle \begin{align*} y^2 + 6y + 2x + 1 &= 0 \\ y^2 + 6y &= -2x - 1 \\ y^2 + 6y + 3^2 &= -2x - 1 + 3^2 \\ \left(y + 3\right)^2 &= -2x+ 8 \\ \left(y + 3\right)^2 - 8 &= -2x \\ x &= -\frac{1}{2}\left(y + 3\right)^2 + 4 \end{align*}

    This is a quadratic. What information can you gain now?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2011
    Posts
    18

    Re: Analytic Geometry- Analyze the equation

    Quote Originally Posted by Prove It View Post
    \displaystyle \begin{align*} y^2 + 6y + 2x + 1 &= 0 \\ y^2 + 6y &= -2x - 1 \\ y^2 + 6y + 3^2 &= -2x - 1 + 3^2 \\ \left(y + 3\right)^2 &= -2x+ 8 \\ \left(y + 3\right)^2 - 8 &= -2x \\ x &= -\frac{1}{2}\left(y + 3\right)^2 + 4 \end{align*}

    This is a quadratic. What information can you gain now?
    Well for this equation I would complete the square. I belive standard form of an elipse will be the result. I do not know how to do this.

    Is that basically what you did?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,656
    Thanks
    1479

    Re: Analytic Geometry- Analyze the equation

    Quote Originally Posted by dazedandmathfused View Post
    Well for this equation I would complete the square. I belive standard form of an elipse will be the result. I do not know how to do this.

    Is that basically what you did?
    I have ALREADY completed the square to give you a QUADRATIC in standard form. A Quadratic is NOT an Ellipse.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5

    Re: Analytic Geometry- Analyze the equation

    Quote Originally Posted by dazedandmathfused View Post
    Well for this equation I would complete the square. I belive standard form of an elipse will be the result. I do not know how to do this.

    Is that basically what you did?
    If you cannot recognise that post # 2 explicitly shows a (sideways) parabola then you need to go back and thoroughly revise your class notes and textbook.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Analytic geometry help?
    Posted in the Geometry Forum
    Replies: 7
    Last Post: July 4th 2009, 10:42 AM
  2. Analytic Geometry Q6
    Posted in the Geometry Forum
    Replies: 3
    Last Post: January 31st 2009, 04:14 AM
  3. Analytic Geometry Q5
    Posted in the Geometry Forum
    Replies: 3
    Last Post: January 31st 2009, 12:53 AM
  4. Analytic Geometry Q4
    Posted in the Geometry Forum
    Replies: 1
    Last Post: January 31st 2009, 12:22 AM
  5. Analytic geometry
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: January 30th 2009, 07:25 PM

Search Tags


/mathhelpforum @mathhelpforum