Special square matrices

Exercise and reference answers

Questions

1. Question

   A diagonal matrix has aᵢⱼ = 0 whenever

   Choices

   1. i = j
   2. i > j
   3. i ≠ j

   Correct choice

   i ≠ j

2. Question

   A scalar matrix has every diagonal entry equal to

   Choices

   1. one constant k
   2. 1
   3. 0

   Correct choice

   one constant k

3. Question

   An identity matrix has diagonal entries equal to

   Choices

   1. 0
   2. 1
   3. k

   Correct choice

   1

4. Question

   A zero matrix has every entry equal to

   Choices

   1. 1
   2. its index
   3. 0

   Correct choice

   0

Explanation