NDA 2025
- Exam
- NDA
- Year
- 2025
- Subject
- Mathematics
- Chapter
- Determinants
NDA 2025 · Mathematics · Determinants
Consider the following statements: Statement-I: If X is an n × n...
Consider the following statements:
Statement-I: If is an matrix, then , where is a scalar.
Statement-II: If is a matrix obtained from by multiplying any row or column by a scalar , then .
Which one of the following is correct in respect of the above statements?
Statement-I: If is an matrix, then , where is a scalar.
Statement-II: If is a matrix obtained from by multiplying any row or column by a scalar , then .
Which one of the following is correct in respect of the above statements?
Options
- ABoth Statement-I and Statement-II are correct and Statement-II explains Statement-I
- BBoth Statement-I and Statement-II are correct but Statement-II does not explain Statement-I
- CStatement-I is correct but Statement-II is not correct
- DStatement-I is not correct but Statement-II is correct
Correct answer
A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
Step-by-step solution
Statement-I states that for an matrix , . This is a standard property of determinants and is correct.
Statement-II states that if a single row or column of a matrix is multiplied by a scalar , the determinant of the resulting matrix is times the determinant of the original matrix. This is also a fundamental property of determinants and is correct.
Multiplying a matrix by a scalar is equivalent to multiplying each of its rows by . By applying the property given in Statement-II times (once for each row), we can factor out from each of the rows, yielding .
Thus, Statement-II provides the logical reasoning required to prove Statement-I. Both statements are correct, and Statement-II explains Statement-I.
Statement-II states that if a single row or column of a matrix is multiplied by a scalar , the determinant of the resulting matrix is times the determinant of the original matrix. This is also a fundamental property of determinants and is correct.
Multiplying a matrix by a scalar is equivalent to multiplying each of its rows by . By applying the property given in Statement-II times (once for each row), we can factor out from each of the rows, yielding .
Thus, Statement-II provides the logical reasoning required to prove Statement-I. Both statements are correct, and Statement-II explains Statement-I.