1. Limited time only! Sign up for a free 30min personal 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!

Finding the intersection points of the two lines in space

  1. Feb 26, 2012 #1
    given the lines in space

    L1 : x = 2t + 1, y = 3t + 2, z = 4t + 3
    L2 : x = s + 2, y = 2s + 4, z = -4s – 1
    Find the point of intersection of L1 and L2.
    How do i solve this?
  2. jcsd
  3. Feb 26, 2012 #2
    set the x's equal to each other and solve for either t or s, then plug in to the other variables to get the coordinates
  4. Feb 26, 2012 #3
    Another method .............
    Set the x's and y's equal to each other
    2t+1 = s+2
    3t+2 = 2s+4
    solve the system for t and s
    Plug the resulting values for t and s in to
    z=4t+3 and z = -4s-1
    to be sure they give the same value for z
    If they do not, the lines are skew
    If they do, then the values for t and s give the
    coordinates of the intersection point for x,y and z
  5. Feb 26, 2012 #4
    thank u very much mr. paulfr and woopydalan...i appreciate your replies to my question.. thank u very much =)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook