Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

suju101

  • 4 years ago

1 2 3 4 5 6 7 8 9 | what is the minor of a22??

  • This Question is Closed
  1. KingGeorge
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    If I'm correct about what a minor is, the minor of \(A_{22}\) would be the determinant of the matrix if you removed the second row and second column. In other words, the minor of \(A_{22}\) would then be \[(1*9)-(3*7) = 9-21=-12\]

  2. suju101
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    are minor and cofactor same thing??

  3. KingGeorge
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Close, but not quite. To get the cofactor, you would then have to multiply your minor by \((-1)^{i+j}\) where \(i, j\) are the indices of the row and column you're removing. In your case, they're both 2, so the cofactor would be \[(-1)^{2+2} * (-12) = (-1)^4 *(-12) = 1*(-12)=-12\]which is indeed the minor, but this is not always the case.

  4. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy