Recent content by MrsM

  1. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    It does, as I'm sure you know. There is no need to be condescending, I'm here for help, not to be judged. It does not however show how to solve for a 3x3 matrix that has 4 unknown coefficient variables. I get that you are trying to help without flat out giving answers, but there are nicer ways...
  2. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    I got so excited. Though I had it... But I didnt, it was wrong. I took the diagonal values and added them to get the trace. I then used that to create a ratio for the determinant. Since I am looking for det of an inverse, I then divided the answer by 1. So: -2.1 + 4.2 + 1.7 3.8 (-1.1)(2.3)x =...
  3. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    Hi Ray, 51st number. The 51th out of a lovely 95 :) but I can totally see why that would make you wonder... cute dog by the way.
  4. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    Ive been thinking about how this math is different from Calc2 and its predecessors, and you are right, please have patience with me as I embark on the process of undoing 14 years worth of being taught "plug and chug"
  5. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    it is the sum of the eigenvalues
  6. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    Yes I did. For the record, our instructor has been MIA for about 4 days and missed the last lecture, so we are afloat... From your question regarding determinants, I realize we are missing a det. I have looked through the entirety of our textbook. every single homework problem and do not see a...
  7. MrsM

    Using eigenvalues to get determinant of an inverse matrix

    Homework Statement Homework Equations determinant is the product of the eigenvalues... so -1.1*2.3 = -2.53 det(a−1) = 1 / det(A), = (1/-2.53) =-.3952 The Attempt at a Solution If it's asking for a quality of its inverse, it must be invertible. I did what I showed above, but my answer was...
  8. MrsM

    Linear Algebra: characteristic polynomials and trace

    So does that mean since they have the same coefficients, the equation is the same? What if the values of x and y are different? Does that make the equation still the same? And since the coefficients are the same, and the trace is represented by the second highest one, does that mean if two...
  9. MrsM

    Linear Algebra: characteristic polynomials and trace

    I found this, because you said to look at a 2x2 and a 3x3, and see if they have something in common, and I am trying to see the correlation, but aside from that they both have something involving Trace in the middle, I don't. I appreciate your help, but at this point I have spent about 2 hours...
  10. MrsM

    Linear Algebra: characteristic polynomials and trace

    Fresh, I don't understand, but I'm definitely trying. I've been up since 3am and have only completed 5 out of 30 questions on this assignment. I am looking at dozens of determinant calculations I have done over the past few weeks using Laplace. They are done correctly, but I am still...
  11. MrsM

    Linear Algebra: characteristic polynomials and trace

    Dear Fresh_42 and Perok, Thank you for responding, the question included no specific matrix. It is a question of concept. I suppose I could try to make one. But I was hoping I could answer using concepts. Perok, I think it is for X^2, Y^2, Z^2 in a 3x3 matrix. Fresh_42, I don't understand...
  12. MrsM

    Linear Algebra: characteristic polynomials and trace

    The question is : Is it true that two matrices with the same characteristic polynomials have the same trace? I know that similar matrices have the same trace because they share the same eigenvalues, and I know that if two matrices have the same eigenvalues, they have the same trace. But I am...
  13. MrsM

    Who is Marisol and Why is She a Valuable Resource for Online Help in Math?

    I'm Marisol and I'm a non traditional student getting a degree in math. I have found that nearly all of my searches for help online somehow lead me here, so I figured I'd become a part of it. Thank you for providing such a valuable resource.
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