Which matrix acts as the multiplicative identity for every 2 × 2 matrix A?
Correct answer: C. [[1, 0], [0, 1]]
- A. [[0, 0], [0, 0]]
- B. [[1, 1], [1, 1]]
- C. [[1, 0], [0, 1]]
- D. [[0, 1], [1, 0]]
Explanation
The 2 × 2 identity matrix has ones on the main diagonal and zeros elsewhere. Multiplying any compatible matrix by it leaves that matrix unchanged.
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