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Jacobian? Determinant

  1. Dec 12, 2012 #1
    Not sure if this is where I should put this but currently im taking math for econ and we are on special determinants (jacobian, Hessian, Bordered Hessian, some Leontiff)

    So I have this problem in my notes that I am basically basing my exam studying around since the book isnt the best. It is a Jacobian heading into a hessian but I am more confused about the Jacobian. So this is what I have

    z = 2x2 + 4y2 - 2xy + 65 + λ(32-x-y)

    zx = 4x - 2y + λ
    zy = 8y - 2x +λ
    zλ = 32-x-y

    Then it goes into the matrice and I have written

    4 -2 -1 x 0
    -2 -8 -1 y = 0
    -1 -1 0 λ -32

    lJl = lAl = -16 ≠ 0 p(a) = 3

    Ok so once I have made the matrice (which makes sense to me) I can even find the determinants of the first part. Im just confused how 0 0 -32 came about and also where the last bit which i assume is the final answer means. I can do a 2x2 Jacobian easily its when it is like this that confuses me. What step am I missing. Also if this is the wrong section I apologize feel free to move it. I just googled how to do something and this was where something on determinants was
  2. jcsd
  3. Dec 12, 2012 #2
    Im sorry I just realized that this should be in Homework help. If a moderator would move it please. I am sorry for cluttering yalls forum.
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