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: Inverse of a Matrix with det=0

  1. Feb 15, 2012 #1
    1. The problem statement, all variables and given/known data

    What is the inverse of matrix A?
    A=

    (1) (2) (1)
    (2) (-1) (2)
    (1) (2) (1)



    2. Relevant equations



    3. The attempt at a solution

    The determinant works out to be 0

    The inverse is 1/determinant x adj(A)

    Therefore the inverse is 1/0 x adj(A)

    So is the answer to, what is the inverse, simply that it is undefined?
     
  2. jcsd
  3. Feb 15, 2012 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Sure. If a matrix has determinant zero then it doesn't have an inverse. It doesn't represent a 1-1 map that can be inverted.
     
  4. Feb 15, 2012 #3
    Thank you
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook