Class 12 Determinants · Conceptual Answer1 Marksadjugate
Class 12 Maths · Determinants · Conceptual Answer #44
For A=\(\begin{bmatrix}2 & 0 & 0\\-1 & 2 & 3\\3 & 3 & 5\end{bmatrix}\), find A adj(A).
✅ Step-by-Step Solution
Final Answer: \(\begin{bmatrix}2 & 0 & 0\\0 & 2 & 0\\0 & 0 & 2\end{bmatrix}\)
- Expanding along the first row gives det(A)=2(10−9)=2. Use A adj(A)=det(A)I₃.
- \(\begin{bmatrix}2 & 0 & 0\\0 & 2 & 0\\0 & 0 & 2\end{bmatrix}\)
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] Expanding along the first row gives det(A)=2(10−9)=2. Use A adj(A)=det(A)I₃.
- [0.5 marks] \(\begin{bmatrix}2 & 0 & 0\\0 & 2 & 0\\0 & 0 & 2\end{bmatrix}\)
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