alleryDeterminant of [[1,2,3],[4,5,6],[7,8,9]]:
A0
B-9
C9
D18
Answer & Solution
Correct answer: A. 0
Notice row 2 - row 1 = [3,3,3], row 3 - row 1 = [6,6,6] = 2 × (row 2 - row 1).
Rows are linearly dependent, so det = 0. (Also from cofactor expansion.)
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