Results 1 to 4 of 4
Like Tree2Thanks
  • 1 Post By Prove It
  • 1 Post By Prove It

Math Help - Unit vectors parallel

  1. #1
    Newbie
    Joined
    Apr 2014
    From
    Sydney, AUS
    Posts
    6

    Unit vectors parallel

    Hi there,

    I need to find two unit vectors parallel to line L, where L is given by x = (z-1)/2, y = 1

    Not sure how to approach the problem, could anybody help?

    Thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,513
    Thanks
    1404

    Re: Unit vectors parallel

    Start by putting the line into its vector form. You need a parameter, say $\displaystyle \begin{align*} t \end{align*}$. So you can set $\displaystyle \begin{align*} x = t \end{align*}$, which means $\displaystyle \begin{align*} \frac{z - 1}{2} = t \implies z = 2t + 1 \end{align*}$.

    So the line can be written as $\displaystyle \begin{align*} L = ( t, 1, 2t + 1 ) = t (1 , 0 , 2 ) + ( 0, 1, 1 ) \end{align*}$.

    So the direction vector of the line is $\displaystyle \begin{align*} (1, 0, 2) \end{align*}$. What is the unit vector going in that direction? What is another unit vector that is parallel to this one?
    Thanks from SydneyGuy
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2014
    From
    Sydney, AUS
    Posts
    6

    Re: Unit vectors parallel

    Quote Originally Posted by Prove It View Post
    Start by putting the line into its vector form. You need a parameter, say $\displaystyle \begin{align*} t \end{align*}$. So you can set $\displaystyle \begin{align*} x = t \end{align*}$, which means $\displaystyle \begin{align*} \frac{z - 1}{2} = t \implies z = 2t + 1 \end{align*}$.

    So the line can be written as $\displaystyle \begin{align*} L = ( t, 1, 2t + 1 ) = t (1 , 0 , 2 ) + ( 0, 1, 1 ) \end{align*}$.

    So the direction vector of the line is $\displaystyle \begin{align*} (1, 0, 2) \end{align*}$. What is the unit vector going in that direction? What is another unit vector that is parallel to this one?
    Ahh I get it now. So the unit vectors parallel would be +(1/sqrt5)(1, 0, 2) and -(1/sqrt5)(1, 0, 2)?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,513
    Thanks
    1404

    Re: Unit vectors parallel

    They're fine, you could also move them around if you want...
    Thanks from SydneyGuy
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: February 15th 2013, 01:01 PM
  2. Finding parallel unit vector
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: November 25th 2011, 12:41 PM
  3. Parallel Vectors
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 22nd 2010, 02:31 PM
  4. Replies: 3
    Last Post: October 4th 2009, 03:08 PM
  5. Vectors - parallel?
    Posted in the Pre-Calculus Forum
    Replies: 5
    Last Post: May 17th 2009, 08:59 AM

Search Tags


/mathhelpforum @mathhelpforum