Results 1 to 3 of 3

Math Help - Linear equation in parametric form

  1. #1
    Junior Member
    Joined
    Sep 2009
    Posts
    34

    Linear equation in parametric form

    Edit: Nvm this post. I figured out what was wrong. doh. Need to figure out how to delete this....

    We have two lines. l1 goes trough the point (3,1) and is parallel with the vector (2,5). Its equation therefore is:
    x = 3 + 2t
    y = 1 + 5t

    The second line l2 goes through the points P1 = (2,1) and P2 = (1, 2). To be able to write its equation we need a vector which is parallel with the line, and P1P2 = (-1,1) is such a vector. Its equation thefefore is:
    x = 1 - t
    y = 2 + t

    But here is my question regarding the equation of the second line. How to know which point P1 or P2 to use to create the equation? Any point that is on the line l2 is supposed to satisfy the equation of the line, and if that is true, should we not be able to pick P1 instead of P2 to create the equation? That is, both the system:
    x = 1 - t
    y = 2 + t
    as well as the system
    x = 2 - t
    y = 1 + t
    should be valid equations for the line?

    If we must be careful about which point we pick, why? How to know which point to pick? Feel like I am missing something obvious here.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Dec 2009
    From
    1111
    Posts
    872
    Thanks
    3
    Dear Sabo,

    Please read the attachment I have given below. If the attachment is not readable of if you have futher queries please don't hesitate to reply me.
    Attached Thumbnails Attached Thumbnails Linear equation in parametric form-dsc02503.jpg  
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Dec 2007
    From
    Ottawa, Canada
    Posts
    3,069
    Thanks
    65
    Quote Originally Posted by Sabo View Post
    Edit: Nvm this post. I figured out what was wrong. doh. Need to figure out how to delete this....
    Better NOT to delete it: may help someone else...
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Parametric form of Quasi Linear PDE
    Posted in the Differential Equations Forum
    Replies: 8
    Last Post: December 23rd 2010, 06:11 AM
  2. parametric form of equation
    Posted in the Calculus Forum
    Replies: 8
    Last Post: April 10th 2010, 11:52 AM
  3. Replies: 1
    Last Post: November 27th 2009, 05:33 PM
  4. Rewrite equation to linear form
    Posted in the Advanced Algebra Forum
    Replies: 0
    Last Post: September 23rd 2009, 07:02 AM
  5. Replies: 4
    Last Post: March 25th 2009, 06:18 PM

Search Tags


/mathhelpforum @mathhelpforum