NDA2017MathematicsMatricesActual

The adjoint of the matrix A= [ array lll 1 & 0 & 2 2 & 1 & 0 0 & 3 & 1 array ] is

Options

A[ array lrr -1 & 6 & 2 -2 & 1 & -4 6 & 3 & 1 array ]
B[ array lcr 1 & 6 & -2 -2 & 1 & 4 6 & -3 & 1 array ]
C[ array rrr 6 & 1 & 2 4 & -1 & 2 6 & 3 & -1 array ]
D[ array lll -6 & 2 & 1 4 & -2 & 1 3 & 1 & -6 array ]

Correct answer

B. [ array lcr 1 & 6 & -2 -2 & 1 & 4 6 & -3 & 1 array ]

Step-by-step solution

aligned & A= [ array lll 1 & 0 & 2 2 & 1 & 0 0 & 3 & 1 array ] & A₁₁=1-0=1 ; A₁₂=-(2-0)=-2 ; A₁₃=6-0=6 & A₂₁=-(0-6)=6 ; A₂₂=1-0=1 ; A₂₃=-3-0=-3 & A₃₁=0-2=-2 ; A₃₂=-(0-4)=4 ; A₃₃=1-0=1 aligned Adj A= [ array ccc 1 & 6 & -2 -2 & 1 & 4 6 & -3 & 1 array ]

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