Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Matrices question

  1. Oct 25, 2008 #1

    rock.freak667

    User Avatar
    Homework Helper

    1. The problem statement, all variables and given/known data

    A square matrix A satisfies the matrix equation A3-3A2+7A-2I=0.
    If A-1 exists, find an expression for A-1 in terms of A and I

    2. Relevant equations



    3. The attempt at a solution

    I just multiplied the matrix equation by A-1 and then rearranged to get

    2A-1 =3A-7I-A2

    Is it that easy? Or is there something that I am missing?
     
  2. jcsd
  3. Oct 25, 2008 #2

    CompuChip

    User Avatar
    Science Advisor
    Homework Helper

    Yes I suppose that is all, although you might want to check your signs.
     
  4. Oct 25, 2008 #3

    rock.freak667

    User Avatar
    Homework Helper

    ok thanks..will do.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook