1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Identity matrix

  1. Feb 18, 2010 #1
    1. The problem statement, all variables and given/known data

    let I_n be as an identity matrix where a_ij = 1 when i=j
    I just want to ask that is it true that all identity matrix has an inverse (determinant is not 0) for n>=2?



    3. The attempt at a solution
     
  2. jcsd
  3. Feb 18, 2010 #2

    CompuChip

    User Avatar
    Science Advisor
    Homework Helper

    The determinant of In is 1, as you can easily compute (expanding along any row or column, you find that det(In) = 1 . det(In - 1) and clearly det(I1) = 1).

    Also it is invertible, and it is its own inverse. You can check this directly from the definition.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Identity matrix
  1. Identity matrix (Replies: 2)

Loading...