Results 1 to 4 of 4

Math Help - Equations of perpeddicual vectors in three-space

  1. #1
    Junior Member
    Joined
    Nov 2009
    Posts
    46

    Equations of perpeddicual vectors in three-space

    the question goes as such: write the parametric equations of the line that goes through point (6, -2, 1) and is perpendicular to both

    f: [x,y,z]=[1, 4, -2] +t[3,-1,1] and
    u: [x,y,z]=[9,5,-3]+s[1,-3,7]

    I think that if a vector is perpendicular to two vectors with different directions then it must be perpendicular at the point where vectors f and u intersect. I think that in this situation I would use the cross product between the two vector f x u to produce the direction vector of the unknown third vector and go from there.
    Last edited by darksoulzero; March 27th 2011 at 12:41 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,139
    Thanks
    1013
    Quote Originally Posted by darksoulzero View Post
    the question goes as such: write the parametric equations of the line that goes through point (6, -2, 1) and is perpendicular to both

    f: [x,y,z]=[1, 4, -2] +t[3,-1,1] and
    u: [x,y,z]=[9,5,-3]+s[1,-3,7]

    I think that if a vector is perpendicular to two vectors with different directions then it must be perpendicular at the point where vectors f and u intersect. I think that in this situation I would use the cross product between the two vectors f x u to produce the direction vector of the unknown third vector and go from there.
    sounds like a plan
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,969
    Thanks
    1788
    Awards
    1
    Quote Originally Posted by darksoulzero View Post
    the question goes as such: write the parametric equations of the line that goes through point (6, -2, 1) and is perpendicular to both
    f: [x,y,z]=[1, 4, -2] +t[3,-1,1] and
    u: [x,y,z]=[9,5,-3]+s[1,-3,7]
    You really need to review this question. Check all the the numbers.
    There is a unique line that is perpendicular to these skew lines.
    However the point (6,-2,1) is not on that line.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Nov 2009
    Posts
    46
    Quote Originally Posted by Plato View Post
    You really need to review this question. Check all the the numbers.
    There is a unique line that is perpendicular to these skew lines.
    However the point (6,-2,1) is not on that line.
    I thought it was weird also, but the numbers are correct. I think there may have been a problem in the printing in the textbook.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Vectors in 3 space
    Posted in the Geometry Forum
    Replies: 8
    Last Post: September 21st 2011, 07:37 PM
  2. Replies: 2
    Last Post: June 18th 2011, 11:31 AM
  3. vectors in 2D space again
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: October 1st 2007, 08:52 AM
  4. Vectors in 2D space
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: September 30th 2007, 10:35 AM
  5. Vectors in 3 space
    Posted in the Calculus Forum
    Replies: 3
    Last Post: December 4th 2006, 06:08 PM

Search Tags


/mathhelpforum @mathhelpforum