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

I Finding the matrix inverse by diagonalisation

  1. Apr 25, 2016 #1
    How would you go about doing this, I see it so often quoted as a method, but no-where can I find an example

    This is what I was thinking


    Would it then follow that D^(-1)=P^(-1)A^(-1)P ?

    My reasoning being:

    DD^(-1)= P^(-1)APP^(-1)A^(-1)P
    identity matrix= P^(-1)AA^(-1)P=identity matrix

    and hence


    Just wondering if this is what they meant or if I've completely missed the point

    Manny thanks in advance :))
  2. jcsd
  3. Apr 25, 2016 #2


    User Avatar
    Science Advisor
    Homework Helper

    Yes, because finding the inverse of a diagonal matrix with all-non-zero diagonal is very easy.
  4. Apr 25, 2016 #3
    Fab - thank you. I just wanted to check :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted