An invertible matrix is said to be nonsingular, and a square matrix with no inverse is called a singular matrix.

Notice that matrix inversion is defined for square matrices only—the condition AA−1 = A−1A rules out inverses of nonsquare matrices.

Although not all matrices are invertible, when an inverse exists, it is unique.

Computing the inverse

Properties of inversion

Products of Nonsingular Matrices Are Nonsingular

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