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!

Plane and 3d vector

  1. Aug 1, 2014 #1
    1. The problem statement, all variables and given/known data
    problem 1:
    given the straight line r whose equation is r=<3+2t, 4+2t, -1-t>

    0.Determine A, intersection of the plane yz
    0.1the parameter value at A is t=
    0.2therefore A=(...,...,...)

    1.we want to re-parametrize r (be u the new parameter) so that:
    1.1the new direction vector e be a unit vector, then e = <...,...,...>
    1.2 as u increases the x coordinates increases. it follows that e=<...,...,...>
    1.3 A be the new origin point. the new equation is: r=<.....,.....,.....>

    2. Determine B and C, intersections of r with the zx and xy plane respectively.
    2.1 parameter values at the two points are Ub=....... Uc=.......
    2.2 distances AB and AC are therefore dAB=.......... dAC=........
    2.3 Points coordinates are B= (.....,.....,.....) C=(......,......,.....)

    3. The attempt at a solution
    A at x=0 hence 3+2t=0 therefore A at t=-3/2
    point A(0,1,1/3)
    direction vector d=(2,2,-1)

    for 1.1 the formula to be applied is v/|v| but i don't know whether it should be applied to the direction vector or to the original equation. also question 1.2 is problematic for me since i don't understand what is asked for. any help is much appreciated
  2. jcsd
  3. Aug 1, 2014 #2


    User Avatar
    Homework Helper

    For 1.1, if t increases, in what direction does the point r(t) travel? They want a unit vector in this direction.
    For 1.2, you may need to flip that vector around so that it points toward the positive x axis.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Plane and 3d vector
  1. Planes in 3D space (Replies: 4)

  2. 3D Vectors (Replies: 4)

  3. 3D vector (Replies: 9)

  4. Vectors in 3D (Replies: 2)