Results 1 to 4 of 4

Math Help - A few matrix checks

  1. #1
    Junior Member
    Joined
    Apr 2008
    Posts
    72

    A few matrix checks

    I have 3 eigenvectors for a matrix M, I have normalised them so that U^t*M*U is a diagonal matrix (U^t is the transpose of U).
    How do i know which eigenvector goes in which column of U.

    Also I have been asked to find the diagonal matrix formed by U^t*M*U.
    Is there any way to make this easier to find, as this will require multiplying a lot of fractions with surds everywhere...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Reckoner's Avatar
    Joined
    May 2008
    From
    Baltimore, MD (USA)
    Posts
    1,024
    Thanks
    75
    Awards
    1

    Smile

    Quote Originally Posted by deragon999 View Post
    I have 3 eigenvectors for a matrix M, I have normalised them so that U^t*M*U is a diagonal matrix (U^t is the transpose of U).
    How do i know which eigenvector goes in which column of U.

    Also I have been asked to find the diagonal matrix formed by U^t*M*U.
    Is there any way to make this easier to find, as this will require multiplying a lot of fractions with surds everywhere...
    U^TMU will be a diagonal matrix, and the entries along the diagonal will be the eigenvalues of M, in whatever order you placed the corresponding eigenvectors in U.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Apr 2008
    Posts
    72
    Thanks, i never knew that.

    Does it not matter the order you put the normalised vectors as columns of U then?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor Reckoner's Avatar
    Joined
    May 2008
    From
    Baltimore, MD (USA)
    Posts
    1,024
    Thanks
    75
    Awards
    1

    Smile

    Quote Originally Posted by deragon999 View Post
    Thanks, i never knew that.

    Does it not matter the order you put the normalised vectors as columns of U then?
    No, but the order you put them in will determine the order of the entries of the diagonal matrix, as I explained.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Data Manag. - Prob. Questions + My views + Checks
    Posted in the Statistics Forum
    Replies: 5
    Last Post: January 5th 2009, 06:45 PM
  2. Integration qs and checks
    Posted in the Calculus Forum
    Replies: 5
    Last Post: June 16th 2008, 11:03 PM
  3. l'hopitals rule checks and help
    Posted in the Calculus Forum
    Replies: 9
    Last Post: May 27th 2008, 09:44 AM
  4. Answer Checks!!
    Posted in the Algebra Forum
    Replies: 5
    Last Post: February 13th 2008, 05:59 AM
  5. secetary periodically checks, check answer please
    Posted in the Statistics Forum
    Replies: 2
    Last Post: August 9th 2006, 08:47 PM

Search Tags


/mathhelpforum @mathhelpforum