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Section 3 .2, problem number 2, properties of determinants.
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So i have to find the determinant of this 3x3 matrix using elementary row operations to get it into upper triangular form.
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So that means that everything below the diagonal becomes a 0, multiply the diagonal to get the determinant.
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So just to start clearing this out.
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If i were to take negative 2 times row 1 and add that to row 2 and place that answer into row 2, that's going to come.
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Clear out this 2 that you see right here.
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So in doing that operation, i have 1, 2, 3.
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So negative 2 times 1 plus 2 is 0.
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Negative 2 times 2 is negative 4.
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Negative 4 plus 6 is 2.
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And then negative 2 times 3 is negative 6.
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Negative 6 plus positive 4 is negative 2.
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Now if i want to clear out this 3, i could take negative 3 times row 1, add that to row 3 and place that answer in row 3.
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And that will clear out the next element for me...