Results 1 to 3 of 3

Math Help - Need help figuring out how to write and equation in the standard form of an ellipse.

  1. #1
    Junior Member
    Joined
    Jan 2011
    Posts
    28

    Need help figuring out how to write and equation in the standard form of an ellipse.

    So I have the equation:
     3x^2+4y^2+8y=8

    I'm pretty sure its an ellipse so I tried to start putting it in the standard form of an ellipse.

    3x^2+4y^2+8y=8
    3x^2+4(y^2+2y+1)=8-4
    3x^2+4(y+1)^2=4
    3x^2/4+(y+1)^2=1
    x^2/4+(y+1)^2/3=1/3

    But how can I make the right side equal 1 instead of 1/3 and not having thing multiplying by x or y?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2009
    Posts
    806
    Thanks
    4
    You can write the last but one step as
    x^2/(4/3) + (y+1)^2 = 1
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Oct 2010
    From
    Heart of Winter
    Posts
    115
    Thanks
    1
    you need to add on both sides. then divide. you would subtract the 4 if it was a function with no '=' sine

    <br />
3x^2+4(y^2+2y+1)=8+4<br />

    <br />
\frac{3x^2}{12}+\frac{4(y+1)^2}{12}=\frac{12}{12}<br />

    <br />
\frac{x^2}{4}+\frac{(y+1)^2}{3}=1<br />
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Converting ellipse equation to standard form
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: December 31st 2010, 09:17 PM
  2. Replies: 3
    Last Post: March 10th 2010, 08:33 AM
  3. Replies: 1
    Last Post: March 9th 2010, 08:48 AM
  4. Replies: 1
    Last Post: February 16th 2010, 07:21 AM
  5. Equation of Ellipse in Standard Form
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 24th 2009, 01:07 PM

Search Tags


/mathhelpforum @mathhelpforum