JEE Main 202228 JuneMorning Shift
- Exam
- JEE Main
- Year
- 2022
- Date
- 28 June
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Matrices
JEE Main 2022 · 28 June · Morning Shift · Mathematics · Matrices
Let A be a matrix of order 3 × 3 and det(A) = 2 . Then det(det ( A...
Let 3 \times 3det\left(A\right) = 2det\left(det ( A ) adj \left(5 adj \left({A}^{3}\right)\right)\right) is equal to _____.
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
(|(\operatorname{det}(5 \operatorname{adj}()
(=\left|2 \operatorname{adj}\left(5 \operatorname{adj}\left(\mathrm{A}^3\right)\right)\right|)
(=2^3 \mid \operatorname{adj}\left(5 \operatorname{adj}\left(\mathrm{A}^3\right) \|\right.)
(=2^3\cdot\left|5 \operatorname{adj}\left(\mathrm{A}^3\right)\right|^2)
(=2^3\left(5^3 \cdot\left|\operatorname{adj}\left(\mathrm{A}^3\right)\right|\right)^2)
(=2^3 5^6 \cdot\left|\operatorname{adj} \mathrm{A}^3\right|^2)
(=2^3 5^6\left(\left(|\mathrm{~A}|^3\right)^2\right)^2)
(=2^3\cdot\cdot\times\times\times10^6)