Results 1 to 2 of 2

Math Help - solution to vector in plane and their sum

  1. #1
    Feb 2011

    solution to vector in plane and their sum

    I'm working on one of Gilbert Strang's exercises on vector subspaces. In the question, there is a vector x+y-2z=4. I need to find a solution and also their sum has to equal zero. I'm not sure if I understand the question:

    Q: Let P be plane in \mathbb{R}^2 with x+y-2z=4 and zero vector is not in P. Find 2 vectors in P and their sum must not be in P.

    I assume that since their sum not in P, then the 2 vectors add to zero vector. I'm having trouble solving the equation to meet the requirements. How do I go about this?

    Follow Math Help Forum on Facebook and Google+

  2. #2
    A Plied Mathematician
    Jun 2010
    CT, USA
    Well, if the sum were equal to zero, that would certainly work. But the sum could be any vector that's not in the plane, and you would have shown that the plane is not a vector subspace. Can you find two vectors in the plane? (Hint: try to find two non-collinear vectors).
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: February 2nd 2011, 05:16 PM
  2. Replies: 11
    Last Post: December 23rd 2009, 02:30 AM
  3. Replies: 2
    Last Post: October 5th 2009, 04:25 PM
  4. Vector equation of a plane
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: May 18th 2009, 04:06 PM
  5. Solution on the Whole Plane
    Posted in the Calculus Forum
    Replies: 0
    Last Post: August 31st 2008, 12:23 PM

Search Tags

/mathhelpforum @mathhelpforum