Question
Download Solution PDFLet X be a matrix of order 3 x 3, Y be a matrix of order 2 x 3 and Z be a matrix of order 3 × 2. Which of the following statements are correct?
I. (ZY)X is defined and is a square matrix of order 3.
II. Y(XZ) is defined and is a square matrix of order 2.
III. X(YZ) is not defined.
Select the answer using the code given below.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept:
Matrix Multiplication:
- Matrix multiplication is defined only when the number of columns in the first matrix is equal to the number of rows in the second matrix.
- For two matrices \( A_{m \times n} \) and \( B_{n \times p} \), their product \( AB \) will result in a matrix \( C_{m \times p} \).
- In general, the product of \( X \) and \( Y \) is defined if and only if the number of columns in \( X \) equals the number of rows in \( Y \).
Calculation:
We have the following matrix operations:
\( A_{m \times n} B_{n \times p} = (AB)_{m \times p} \)
Now, consider the matrix multiplications:
\([Z_{3 \times 2} . Y_{2\times3}].X_{3 \times 3}] = [ZYX]_{3 \times 3}\)
\( Y_{2 \times 3} [X_{3 \times 3} Z_{3 \times 2}] = [YXZ]_{2 \times 2} \)
Finally, we observe that:
\( X_{3 \times 3} [Y_{2 \times 3} Z_{3 \times 2}] = X_{3 \times 3} [YZ]_{2 \times 2} \)
Conclusion:
\(\text{No. of columns in X} \neq \text{No. of rows in (YZ)}\)
Hence, X(YZ) is not defined.
∴ the Correct answer is Option 4
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