Class 12 Matrices · Conceptual Answer1 Marksmatrix_polynomials
Class 12 Maths · Matrices · Conceptual Answer #47
For A=\(\begin{bmatrix}2 & 0 & 1\\2 & 1 & 3\\1 & -1 & 0\end{bmatrix}\), find A²−5A.
✅ Step-by-Step Solution
Final Answer: \(\begin{bmatrix}-5 & -1 & -3\\-1 & -7 & -10\\-5 & 4 & -2\end{bmatrix}\)
- First A²=\(\begin{bmatrix}5 & -1 & 2\\9 & -2 & 5\\0 & -1 & -2\end{bmatrix}\); subtract 5A=\(\begin{bmatrix}10 & 0 & 5\\10 & 5 & 15\\5 & -5 & 0\end{bmatrix}\) entry by entry.
- \(\begin{bmatrix}-5 & -1 & -3\\-1 & -7 & -10\\-5 & 4 & -2\end{bmatrix}\)
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] First A²=\(\begin{bmatrix}5 & -1 & 2\\9 & -2 & 5\\0 & -1 & -2\end{bmatrix}\); subtract 5A=\(\begin{bmatrix}10 & 0 & 5\\10 & 5 & 15\\5 & -5 & 0\end{bmatrix}\) entry by entry.
- [0.5 marks] \(\begin{bmatrix}-5 & -1 & -3\\-1 & -7 & -10\\-5 & 4 & -2\end{bmatrix}\)
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