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!

3d equations of planes

  1. Oct 31, 2005 #1
    hi all im struggling to on these types of questions ill post here

    1. find the equation of the plane containing the points A(-1,2,1) B(0,2,3) and C(4,-1,2)

    i tried to plot this on a x,y,z and maybe i rearranged to get formula n=CA * CB but its wrong heh no idea how to do this anyone can help me out thanks heapsss!
     
  2. jcsd
  3. Oct 31, 2005 #2
    use A and B to find vector AB and then find vector AC (AB = B - A and AC = C - A)

    now the vector equation is in this form

    (x,y,z) = ( a1, a2, a3 ) + s( ab1, ab2, ab3, ) + t(ac1, ac2, ac3)

    from here you can find you parametric and symetric equations and further you can do find the cross product to find the normal vectors and find the scalar eqatuin in the form of Ax + By + cz + D = 0

    look in the text book
     
  4. Nov 1, 2005 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    I presume you meant n= CA X CB where X is the cross product.

    Show us what you did: what CA and CB are and how you did the cross product.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?