Question 5 • Advanced Algebra: Concepts and Connections
Which expression represents the determinant of cap A is equal to the 2 by 2 matrix, row 1, column 1, negative 3 column 2, 6 row 2, column 1, 1 column 2, negative 6 ?
Answer
A
det times cap A is equal to negative 3 times negative 6 minus 1 times 6
B
det times cap A is equal to negative 3 times negative 6 plus 1 times 6
C
det times cap A is equal to 1 times 6 minus negative 3 times negative 6
D
det times cap A is equal to negative 3 times negative 6 plus negative 1 times negative 6
Explanation
For a 2 by 2 matrix [?]determinant, use ad − bc: multiply the top-left and bottom-right entries, then subtract the product of the other two entries. Here that gives (−3)(−6) − (6)(1), which matches choice B.
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