Results 1 to 3 of 3

Math Help - New to vectors

  1. #1
    Newbie
    Joined
    Mar 2008
    Posts
    6

    New to vectors

    Hey guys, I'm in year 9 and our teacher gave us some extension work and it's on vectors which we've never done before. These questions are probably really basic but it would be great if you could give me a hand with them

    2. Given the vector (-5,12) find the following vectors:

    a) same direction, twice as long
    b)same direction, length 1
    c) opposite direction, length 10
    d) opposite direction, length c

    Im really lost on the above ones

    4. Find the lengths of the following vectors:
    a) (3,4)
    From what i've tried to read on wiki the answer to this is 5 (pythagoras)
    b) 1998(3,4)
    I don't understand what a number in front means
    c) 1998/5 (3,4)
    d) t(3,4)

    Thanks heaps guys
    Last edited by IndoorKid; May 10th 2009 at 03:54 AM. Reason: formatting
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,617
    Thanks
    1582
    Awards
    1
    Quote Originally Posted by IndoorKid View Post
    2. Given the vector (-5,12) find the following vectors:
    a) same direction, twice as long
    b)same direction, length 1
    c) opposite direction, length 10
    d) opposite direction, length c
    The vector \left\langle { - 5,12} \right\rangle has length \left\| {\left\langle { - 5,12} \right\rangle } \right\| = \sqrt {( - 5)^2  + \left( {12} \right)^2 }  = 13

    What are the lengths of \left\langle { - 10,24} \right\rangle \;\& \;\left\langle {\frac{{ - 5}}{{13}},\frac{{12}}{{13}}} \right\rangle ?

    Why is the vector \left\langle {50, - 120} \right\rangle oppsite in direction to the given vector?
    What is its length?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Lord of certain Rings
    Isomorphism's Avatar
    Joined
    Dec 2007
    From
    IISc, Bangalore
    Posts
    1,465
    Thanks
    6
    Quote Originally Posted by IndoorKid View Post
    4. Find the lengths of the following vectors:
    a) (3,4)
    From what i've tried to read on wiki the answer to this is 5 (pythagoras)
    b) 1998(3,4)
    I don't understand what a number in front means
    c) 1998/5 (3,4)
    d) t(3,4)

    Thanks heaps guys
    * Draw a picture of co-ordinate axes and locate the point. This will help you see why pythogorus theorem is applied.

    * t(3,4) is a notation for (3t,4t). For example 6(3,4) = (18,24)

    Use the above suggestions to solve the problem. Do post your attempts
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: November 15th 2011, 05:10 PM
  2. Replies: 3
    Last Post: June 30th 2011, 08:05 PM
  3. Replies: 2
    Last Post: June 18th 2011, 10:31 AM
  4. [SOLVED] Vectors: Finding coefficients to scalars with given vectors.
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: January 23rd 2011, 12:47 AM
  5. Replies: 4
    Last Post: May 10th 2009, 06:03 PM

Search Tags


/mathhelpforum @mathhelpforum