1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question on Planes

  1. Sep 23, 2006 #1
    The general equation for a plane is ax + by + cz = k, where a, b, c, k are constants, and the plane is satisfied by points (x,y,z). If a specific plane contains both points (2, 1, 3) and (2, 1, 5), what is the value of c?

    The answer is supposed to be c = 0, but I don't know how to get there.

    I tried this [(2, 1, 3)-(2, 1, 5)]t + (2, 1, 5) so I get

    x = 2
    y = 1
    z = 5 - 2t

    but I don't know what to do from there
     
  2. jcsd
  3. Sep 23, 2006 #2

    LeonhardEuler

    User Avatar
    Gold Member

    This is the parametric equation for a line, you want to describe a plane. Two points do not give a full description of a plane, so given two arbitrary points you would generally not be able to find 'c' in the equation. But in this particular case, you will see that if you plug in those two points to the original the equation things will cancel out and you'll be able to find 'c'.
     
  4. Sep 23, 2006 #3
    it's a system of linear equations:
    you have:
    2a+b+3c=k
    2a+b+5c=k
    solve it and get your answer.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Question on Planes
  1. Plane question (Replies: 4)

  2. Tangent plane question (Replies: 1)

Loading...