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!

3-dimensional Vector problem.

  1. Mar 12, 2007 #1
    1. The problem statement, all variables and given/known data

    Given the vectors: V1=(3,1,2) and V2=(2,2,-1), find the set of vectors which are coplanar with V1 and V2 and also perpendicular to V3=(-2,1,1). Then Find the members of this set which have length 2-Root-11

    2. Relevant equations

    Dot and cross product

    3. The attempt at a solution

    well, a set of vectors coplanar to v1 and v2 would be V = (x,y,z) = (x',y',z') + rV1 +sV2
    and a vector perpendicular to v3 in the set of vectors coplanar with v1 and v2 is: V X V3.
    But what do i do with the 2-root-11?
     
    Last edited: Mar 12, 2007
  2. jcsd
  3. Mar 12, 2007 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    VxV3 is not necessarily coplanar with V1 and V2. It's just perpendicular to whatever V you choose. Can you think of an expression using a dot product to express V perpendicular to V3? Finally the length of a vector is sqrt(v.v), right?
     
  4. Mar 12, 2007 #3
    okay, ill try it that way...
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: 3-dimensional Vector problem.
  1. Calc 3, vector problem (Replies: 2)

Loading...