Recent content by earti193

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    Determining if a 3x3 matrix is negative semidefinite

    I've gone over the original matrix a few times and can't see how it can be any different. I think that these are constrained optimums because they are optimum demand functions. The matrix is a Skutsky matrix which by definition is identical to the Hessian of the expenditure function. If my...
  2. E

    Determining if a 3x3 matrix is negative semidefinite

    Homework Statement I have the matrix A = [-10 3.5 3; 3.5 -4 0.75; 3 0.75 -0.75] I need to determine whether this is negative semidefinite. Homework Equations The Attempt at a Solution 1st order principal minors: -10 -4 -0.75 2nd order principal minors: 2.75 -1.5...