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If A is a square matrix such that A^2=1 where I is the identity matrix, then what is A ⁻¹ equal to?

Options

  1. AA+1
  2. BNull matrix
  3. CA
  4. DTranspose of A

Correct answer

C. A

Step-by-step solution

aligned A ^2 & = I A ^2 ~A ⁻¹ & = IA ⁻¹ ~A & = A ⁻¹ . aligned

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