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!

Homework Help: Find a Vector parallel to the line of intersection

  1. Sep 21, 2011 #1
    1. The problem statement, all variables and given/known data
    Find a vector parallel to the line of intersection of the planes given by the equations 2x-3y+5z=2 and 4x+y-3z=7.

    2. Relevant equations
    How do I go about this? I know we have two vectors <2,3,5> and <4,1,-3> but where do I go from here?

    3. The attempt at a solution

    I don't know whether I dot this, cross product this. I'm lost as where to go from here.
  2. jcsd
  3. Sep 21, 2011 #2


    User Avatar
    Homework Helper

    note that the line is parallel to both planes. so it is perpendicular to both planes' normals. If you can find the normal of each planes (which you have), how can you use those 2 vectors to find a vector perpendicular to both?
    Last edited: Sep 21, 2011
  4. Sep 21, 2011 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I'm sure you mean both planes normals. :wink:
  5. Sep 21, 2011 #4


    User Avatar
    Homework Helper

    cheers, updated it
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook