NDA 2017
- Exam
- NDA
- Year
- 2017
- Subject
- Mathematics
- Chapter
- Matrices
NDA 2017 · Mathematics · Matrices
Consider the set A of all matrices of order 3 × 3 with entries 0 or...
Consider the set A of all matrices of order with entries 0 or 1 only. Let be the subset of consisting of all matrices whose determinant is 1. Let C be the subset of A consisting of all matrices whose determinant is -1. Then which one of the following is correct?
Options
- AC is empty
- BB has as many elements as C
- C
- DB has thrice as many elements as C
Correct answer
B. B has as many elements as C
Step-by-step solution
determinant of
Let ' ' be identity matrix
So, B=\left|\right|
If we interchange any 2 rows, determinant will be -1
Let, \mathrm{C}=\left|\right|,|\mathrm{C}|=-1
Here, number of elements in B and C are equal.