Answer: 3.
- A 3
- B 9
- C 6
- D 1
Correct answer: A. 3
Explanation: An n×n matrix has n elements on its main diagonal, so a 3×3 matrix has 3.
Element aij of matrix A sits at the intersection of row i and column j.
Concept context
Matrix operations, determinants, inverses, and solving linear systems