1. Limited time only! Sign up for a free 30min personal 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!

A matrix issue

  1. Jun 27, 2009 #1
    1. The problem statement, all variables and given/known data
    So I'm doing a systems of DEs question with undetermined coefficients. After comparing coefficients, I have this:
    a+b=Ab+(1,0)T

    where a&b are vectors (2D) and A is the coefficient matrix:
    [2 -1]
    [3 -2]

    I know that 'a' is (1,1)T. I need to find b.

    I tried rearranging it, but I don't know if that's right.
    (1,1)-(1,0)=Ab-b
    (0,1)=(A-1)b

    So I found A-I:
    [1 -1]
    [3 -3]

    I was going to invert it and multiply by (0,1), but it's not invertible. What do I do?
     
  2. jcsd
  3. Jun 27, 2009 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Hi Melawrghk! :wink:
    Yes, that's fine! :smile:
    Give up! :biggrin:

    A - I is a projection onto the line x = y (because it sends (p,q) to (p-q,p-q)), so you can't have (A - I)b = (0,1).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: A matrix issue
  1. Laplace issue (Replies: 2)

  2. Issue with notation (Replies: 7)

  3. Cardoid issue (Replies: 1)

  4. Induction Issue (Replies: 4)

Loading...