1.   Determine which matrix is the 3 × 3 identity matrix.
    A. B.
    C. D.
    Hint

  2.   Find the inverse of
    A. B.
    C. D.
    Hint

  3.   Determine whether the pair of matrices are inverses.
    A. no, because A · B I B. yes, because A · B = I.
    C. no, because fractions cannot be a part of an inverse D. yes, because each entry in the second matrix is the reciprocal of its corresponding entry in the first matrix.
    Hint

  4.   In order for a matrix to have an inverse, what must be true?
    A. adbc = 1 B. adbc 0
    C. adbc = 0 D. adbc 1
    Hint

  5.   What is the 4 × 4 identity matrix?
    A. B.
    C. D.
    Hint



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