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Homework Help: Quadric surface question, given 3x3 matrix A and (x^T)Ax=6

  1. Jul 10, 2011 #1

    this is my working out:


    i sort of figured out how to do this a few mins ago lol. it doesnt seem too hard.
    it's sort of like... multiplying the first number in the matrix A by it's position in the matrix (x1 * x1) which is basically the coordinates of the value, then doing that for all numbers in the matrix A.

    am i right? have i fully answered the question?

    edit: in my working out, the xTAx = sigma sigma axx was taken from my course manual.
  2. jcsd
  3. Jul 10, 2011 #2


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    Homework Helper

    haven't followed it all through, but i think you have the right idea

    the sigma sigma is just matrix multiplication
  4. Jul 10, 2011 #3
    awesome, thank you :)
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