JEE MainMathematicsMatrices and DeterminantsMCQ+4 / −1
Let and be two symmetric matrices of order . Statement - 1 : and are symmetric matrices. Statement - 2 : is symmetric matrix if matrix multiplication of with is commutative.
- Astatement - 1 is true, statement - 2 is true; statement - 2 is not a correct explanation for statement - 1.
- Bstatement - 1 is true, statement - 2 is false.
- Cstatement - 1 is false, statement -2 is true
- Dstatement -1 is true, statement - 2 is true; statement - 2 is a correct explanation for statement - 1.
View written solutionFree
Correct answer: A
-
Given:
- and are symmetric matrices of order .
- So,
-
Statement–1: and are symmetric matrices
First note that matrix multiplication is associative, so
Now check symmetry of : Since and are symmetric, Hence is symmetric.
Therefore both and are symmetric matrices.
So, Statement–1 is true.
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Statement–2: is symmetric if matrix multiplication of with is commutative
If multiplication is commutative, then
Now, Since , Hence is symmetric.
So, Statement–2 is true.
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Does Statement–2 explain Statement–1?
Statement–2 says: if , then is symmetric.
But Statement–1 concerns the matrix and its symmetry follows directly from without needing .
So Statement–2 is not the correct explanation of Statement–1.
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Conclusion
- Statement–1: True
- Statement–2: True
- Statement–2 is not the correct explanation for Statement–1.
Therefore, the correct option is A.
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