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How can a nonsingular matrix be used to solve a matrix equation?

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A square matrix is considered nonsingular if its determinant is not equal to zero. For such a matrix, there exists an inverse matrix, denoted as A−1, which satisfies the condition AA−1=A−1A=I, where I is the identity matrix.12

To solve a matrix equation of the form AX=B (where A and B are known matrices and X is the unknown), you can utilize the nonsingular property of A to isolate X:

  1. Multiply both sides of the equation on the left by the inverse matrix A−1:
    A−1(AX)=A−1B
  2. Apply the associative law of matrix multiplication:
    (A−1A)X=A−1B
  3. Since A−1A=I and IX=X, the equation simplifies to:
    X=A−1B

This method provides a unique solution for the unknown matrix X.1