Class 12 Matrices · Conceptual Answer1 Marksmatrix_polynomials
Class 12 Maths · Matrices · Conceptual Answer #48
If A²=A, simplify 7A−(I+A)³.
✅ Step-by-Step Solution
Final Answer: −I
- Since A commutes with I, (I+A)³=I+3A+3A²+A³=I+7A, using A²=A and A³=A.
- −I
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] Since A commutes with I, (I+A)³=I+3A+3A²+A³=I+7A, using A²=A and A³=A.
- [0.5 marks] −I
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