Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Physical meaning of directrix?

  1. Sep 13, 2009 #1
    I suddenly realized that the very notion of a directrix seems odd to me.

    (1) I don't know any physical significance of such a thing

    (2) How anyone came to define the parabola as such

    Any help? I read some older posts about the history of the directrix/focus definitions of the conic sections and I can see the idea of unifying the conics through the ratio of distances from a point to the focus and from the point to the directrix but perhaps there is something more, something deeper, something physical?

    Cheers,

    Kevin
     
  2. jcsd
  3. Sep 13, 2009 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Last edited by a moderator: Apr 24, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Physical meaning of directrix?
Loading...