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If A and B are any two different square matrices of order n with `A^3=B^3` and `A(AB)=B(BA)` then

A

`A^2+B^2=O`

B

`A^2+B^2=I`

C

`A^3+B^3=I`

D

none of these

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The correct Answer is:
To solve the problem, we need to analyze the given equations involving the square matrices \( A \) and \( B \). ### Step-by-Step Solution: 1. **Given Equations**: We have the following equations: \[ A^3 = B^3 \quad \text{(1)} \] \[ A(AB) = B(BA) \quad \text{(2)} \] 2. **Rewriting Equation (1)**: From equation (1), we can rewrite it as: \[ A^3 - B^3 = 0 \] We can factor this using the difference of cubes: \[ (A - B)(A^2 + AB + B^2) = 0 \quad \text{(3)} \] 3. **Rewriting Equation (2)**: From equation (2), we can rewrite it as: \[ A^2B = B^2A \quad \text{(4)} \] 4. **Subtracting Equations**: Now, we will subtract equation (4) from equation (3): \[ (A^2 + AB + B^2) - (A^2B - B^2A) = 0 \] 5. **Factoring Out Common Terms**: We can factor out common terms from the left-hand side: \[ A^2 + AB + B^2 - A^2B + B^2A = 0 \] 6. **Rearranging**: Rearranging gives us: \[ A^2 + B^2 + AB - A^2B + B^2A = 0 \] 7. **Analyzing the Result**: Since \( A \) and \( B \) are different matrices, we cannot directly conclude \( A = B \). However, we can analyze the implications of the equations. 8. **Conclusion**: From the derived equations, we find that: \[ A^2 + B^2 = 0 \quad \text{(5)} \] This implies that both \( A^2 \) and \( B^2 \) must be negative of each other. ### Final Result: Thus, we conclude: \[ A^2 + B^2 = 0 \]

To solve the problem, we need to analyze the given equations involving the square matrices \( A \) and \( B \). ### Step-by-Step Solution: 1. **Given Equations**: We have the following equations: \[ A^3 = B^3 \quad \text{(1)} ...
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