InterviewSolution
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Find the determinant of the matrix \(\begin{vmatrix} \rm x-y & \rm y-z & \rm z-x\\ \rm y-z & \rm z-x & \rm x-y \\ \rm z-x & \rm x-y & \rm y-z \end{vmatrix}\)1. x + y + z2. x2 + y2 + z23. 04. (x + y + z)2 - xyz |
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Answer» Correct Answer - Option 3 : 0 Concept: Properties of Determinant of a Matrix:
Calculation: \(\begin{vmatrix} \rm x-y & \rm y-z & \rm z-x\\ \rm y-z & \rm z-x & \rm x-y \\ \rm z-x & \rm x-y & \rm y-z \end{vmatrix}\) Apply R1 → R1 + R2 + R3, We get = \(\begin{vmatrix} \rm 0 & \rm 0 & \rm 0\\ \rm y-z & \rm z-x & \rm x-y \\ \rm z-x & \rm x-y & \rm y-z \end{vmatrix}\) As we can see that the entry of the first row is zero. We know that, If each entry in any row or column of a determinant is 0, then the value of the determinant is zero. ∴ \(\begin{vmatrix} \rm x-y & \rm y-z & \rm z-x\\ \rm y-z & \rm z-x & \rm x-y \\ \rm z-x & \rm x-y & \rm y-z \end{vmatrix}\) = 0 |
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