Minors and cofactors

Exercise and reference answers

Questions

1. Question

   How is the minor M₂₃ formed?

   Choices

   1. Delete row 3 and column 2
   2. Delete column 2 only
   3. Delete row 2 and column 3

   Correct choice

   Delete row 2 and column 3

2. Question

   Cofactor A₂₃ equals

   Choices

   1. −M₂₃
   2. M₂₃
   3. 2M₃

   Correct choice

   −M₂₃

3. Question

   Cofactor A₂₂ equals

   Choices

   1. −M₂₂
   2. M₂₂
   3. 0

   Correct choice

   M₂₂

4. Question

   The sign attached to a cofactor is

   Choices

   1. (−1)^(i×j)
   2. always negative
   3. (−1)^(i+j)

   Correct choice

   (−1)^(i+j)

Explanation