Results 1 to 4 of 4

Math Help - Vector perpendicular

  1. #1
    Member
    Joined
    Jun 2009
    Posts
    110

    Vector perpendicular

    Find the vector perpendicular to the line 3x-5y+2=0.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,824
    Thanks
    1717
    Awards
    1
    Quote Originally Posted by johnsy123 View Post
    Find the vector perpendicular to the line 3x-5y+2=0.
    The line 5x+3y+2=0 is perpendicular to that line.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,697
    Thanks
    1512
    Quote Originally Posted by johnsy123 View Post
    Find the vector perpendicular to the line 3x-5y+2=0.
    Write in the form y = mx + c, i.e. y = (3/5)x + 2/5, which has gradient = 3/5.

    The gradients of perpendicular lines have a product of -1. So the gradient of your perpendicular is -5/3.

    So any line in the family of lines y = (-5/3)x + c will be perpendicular. For simplicity we'll just consider y = (-5/3)x.

    If you note from the slope that this perpendicular line moves down 5 units as you move to the right 3 units, then you can write this line in its vector form t(3i - 5j), where t is an arbitrary constant. If you know a point that this line goes through, say (x_0, y_0), then the line can be written as (x_0 + 3t)i + (y_0 - 5t)j.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by johnsy123 View Post
    Find the vector perpendicular to the line 3x-5y+2=0.
    If the vector (x, y) denotes the staionary vector of any point on the given line then the equation of the line is the result of a scalar product:

    (3, -5) . (x, y) = -2

    where the vector (3, -5) is the normal vector, that means it is perpendicular to the line.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Basis for a perpendicular vector
    Posted in the Advanced Algebra Forum
    Replies: 3
    Last Post: May 4th 2011, 05:48 PM
  2. Replies: 8
    Last Post: January 11th 2011, 10:17 AM
  3. Replies: 11
    Last Post: December 23rd 2009, 01:30 AM
  4. Perpendicular Vector
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 7th 2008, 06:54 PM
  5. The perpendicular distance-vector
    Posted in the Geometry Forum
    Replies: 1
    Last Post: July 24th 2006, 05:46 AM

Search Tags


/mathhelpforum @mathhelpforum