If A = bmatrix 2 & 3 \ 3 & 5 bmatrix, then the determinant of the matrix (A2025 - 3 A2024 + A2023 ) is
- 12
- 24
- 28
- 16
Answer
(4) 16
Solution
|A| = 10 - 9 = 1, tr A = 7
Cayley–Hamilton: A2 - 7A + I = O
A2 - 3A + I = 4A
A2025 - 3A2024 + A2023 = A2023(A2 - 3A + I) = A2023(4A) = 4 A2024
|4 A2024| = 42 |A|2024 (A is of order 2)
= 16 1 = 16
Answer: (4)