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AP EAMCET2005MathematicsMatrices

adj [ array ccc 1 & 0 & 2 -1 & 1 & -2 0 & 2 & 1 array ]= [ array ccc 5 & a & -2 1 & 1 & 0 -2 & -2 & b array ], then [ array ll a & b array ] is equal to

Options

  1. A[− 4 1]
  2. B[− 4 −1]
  3. C[4 1]
  4. D[4 −1]

Correct answer

C. [4 1]

Step-by-step solution

Given that aligned & Cofactor of [ array ccc 1 & 0 & 2 -1 & 1 & -2 0 & 2 & 1 array ] are & C₁₁=5, C₁₂=1, C₁₃=-2 & C₂₁=4, C₂₂=1, C₂₃=-2 & C₃₁=-2, C₃₂=0, C₃₃=1 & [ array ccc 5 & 4 & -2 1 & 1 & 0 -2 & -2 & 1 array ]= [ array ccc 5 & a & -2 1 & 1 & 0 -2 & -2 & b array ] aligned On comparing the corresponding elements, we get array rlrl & a & =4, b=1 & [ array ll a & b array ] & = [ array ll 4 & 1 array ] array

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