Results 1 to 2 of 2

Math Help - unitary and upper triangular matrix => diagonal matrix

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    104

    unitary and upper triangular matrix => diagonal matrix

    How could I prove that a unitary and upper triangular matrix A MUST be a diagonal matrix?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Banned
    Joined
    Oct 2009
    Posts
    4,261
    Quote Originally Posted by dannyboycurtis View Post
    How could I prove that a unitary and upper triangular matrix A MUST be a diagonal matrix?

    U unitary \Longrightarrow U^{*}=U^{-1}\Longrightarrow also U^{*} , in a rather trivial way, is unitary, but it is LOWER triangular , and since the inverse of an upper triangular (invertible ) matrix is upper triangular then...

    Tonio
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: January 18th 2011, 08:24 PM
  2. Upper Triangular Matrix
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: October 20th 2010, 09:06 AM
  3. Replies: 7
    Last Post: September 2nd 2009, 10:03 AM
  4. Unitary and triangular = diagonal matrix
    Posted in the Advanced Algebra Forum
    Replies: 4
    Last Post: April 13th 2009, 03:18 AM
  5. Replies: 1
    Last Post: February 23rd 2009, 07:24 PM

Search Tags


/mathhelpforum @mathhelpforum