If A and B are two matrices conformable to multiplication such that th...
AB = 0 does not necessarily imply that either A or B is a null matrix
- Both matrices need not be null matrices.
If A and B are two matrices conformable to multiplication such that th...
Explanation:
When two matrices A and B are multiplied, the resulting matrix will have the same number of rows as A and the same number of columns as B. If the product of two matrices AB is a zero matrix, then it means that all the entries of the resulting matrix are zero. This condition implies that the product of any row of A with any column of B results in zero.
Possible Cases:
1. A and B are both null matrices:
If both matrices A and B are null matrices, then their product AB will also be a null matrix. This condition satisfies the given statement. Hence, option A is correct.
2. Either of A is or B is a null matrix:
If either matrix A or B is a null matrix, then their product AB will also be a null matrix. This is because the product of any non-zero matrix with a null matrix results in a null matrix. Hence, option B is correct.
3. Neither of them may be a zero matrix:
It is possible that neither matrix A nor B is a null matrix, but their product AB is still a null matrix. For example, consider the matrices A = [1 0] and B = [0 0; 0 0]. Their product AB = [0 0; 0 0] is a null matrix. Hence, option C is not always correct.
Conclusion:
From the above analysis, we can conclude that options A, B, and C are not mutually exclusive. Hence, option D, i.e., all of the above options are correct, is the correct answer.