Results 1 to 4 of 4

Math Help - Ellipse -semimajor-seminor axes help!!!

  1. #1
    Newbie
    Joined
    Sep 2007
    Posts
    23

    Ellipse -semimajor-seminor axes help!!!

    Hi,

    Assume we have an ellipse (positioned somewhere in 3d space) and I also have a vector pointing towards the center of the ellipse. How can I specify in 3d rectangular coordinates the directions of the major and minot axes knowing the center of the ellipse?

    Thanks

    Regards

    Alex
    Last edited by tecne; November 20th 2007 at 02:15 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    Do you know anything else about the ellipse? It's pretty tough if only the center is known.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Sep 2007
    Posts
    23
    Hi,

    Thanks for your reply. No I dont know anything else. I only know that there exists a vector that points towards the center of the ellipse. From this I would like to find out the major and minor axes directions.

    Say for example that the center is at [1 0 0].

    Thanks again

    Regards

    Alex
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    So, you're saying you want a vector to point to something you don't know. You don't know even the length of the axes or the orientation of the ellipse? It makes no sense. Why would it be possible?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Translation of axes
    Posted in the Geometry Forum
    Replies: 1
    Last Post: June 23rd 2009, 04:23 PM
  2. rotation of axes
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: May 11th 2009, 08:37 PM
  3. Replies: 2
    Last Post: December 19th 2008, 05:01 AM
  4. Semi-axes of an ellipse
    Posted in the Advanced Math Topics Forum
    Replies: 0
    Last Post: October 25th 2007, 11:47 AM
  5. ellipse axes
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 19th 2006, 05:16 AM

Search Tags


/mathhelpforum @mathhelpforum