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!

Complex Eigenvectors

  1. Nov 27, 2006 #1

    I have a quick question that I can not seem to find much of an answer to in my text. When working with a nxn matrix, A, and you find eigenvalues that are complex, I'm confused about how to go about finding the actual eigenvector. I know we compute the null space of A-lambdaI, but that is where I seem to get stuck. For a 2x2, easy enough and I can do it. The problem is when n > 2. Gaussian elimination becomes a ridiculous mess. Is that the only way to do it? When I do substitution I end up with 0 = 0 which makes me think that each row is just some multiple of the other. If this is the case, do I just use any row I want?

    Basically, I'm completely stuck with how to solve the complex matrix.

    Any help would be greatly appreciated! :uhh:
  2. jcsd
  3. Nov 28, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    Well, of course, you get "0= 0". In order to be an eigenvalue, the equations you get with [itex]\lambda[/itex] equal to that eigenvalue, must be dependent so that 0 is not the only solution. I don't know what problem you are doing but Gaussian elimination is the best way to go- expect, of course, to use a TI-93 calculator that will do eigenvectors for you!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Complex Eigenvectors