Adjoint and identity

Exercise and reference answers

Questions

1. Question

   A (adj A) equals

   Choices

   1. |A| I
   2. I
   3. adj A

   Correct choice

   |A| I

2. Question

   (adj A) A equals

   Choices

   1. A
   2. |A| I
   3. 0

   Correct choice

   |A| I

3. Question

   If AB = BA = I then B is

   Choices

   1. the adjoint of A
   2. the transpose of A
   3. the inverse of A

   Correct choice

   the inverse of A

4. Question

   (A⁻¹)⁻¹ equals

   Choices

   1. A
   2. I
   3. adj A

   Correct choice

   A

Explanation