The determinant of a 3 × 3 matrix A is defined as follows.

The determinant of a 3 × 3 matrix can also be found using the method of “diagonals.”

Step 1 Rewrite columns 1 and 2 of matrix A to the right of matrix A.

Step 2 Identify the diagonals d₁ through d₆ and multiply their elements.

Step 3 Find the sum of the products from d₁, d₂, and d₃.

Step 4 Subtract the sum of the products from d₄, d₅, and d₆ from that sum:

(d₁ + d) + d₃) - (d₄ + d₅ + d₆).

Verify that this method produces the same results as the previous method given.

Transcribed Image Text:

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