Determinant of a 3x3 Matrix using the Diagonal Method

The video tutorial explains how to find the determinant of a 3x3 matrix using the diagonal method, also known as the lattice method. It begins by extending the matrix by rewriting the first two columns at the end. The process involves multiplying elements along the down diagonals and then the up diagonals. The sums of these products are calculated, and the determinant is found by subtracting the sum of the up diagonals from the sum of the down diagonals. The final determinant of the matrix is determined to be 1.

What is another name for the diagonal method used to find the determinant of a 3x3 matrix?

• Grid method

• Row method

• Lattice method

• Column method

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CCSS.HSN.VM.C.8

What is the first step in extending the matrix for the diagonal method?

• Adding a new column at the side

• Rewriting the first two columns at the end

• Rewriting the last two columns at the start

• Adding a new row at the bottom

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CCSS.6.NS.B.3

When calculating the downward diagonals, what is the product of the first diagonal?

• Positive 4

• Negative 4

• Zero

• Positive 3

What is the sum of the products of the downward diagonals?

• 3

• 4

• 5

• 6

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CCSS.3.OA.D.9

In the upward diagonal calculation, what is the product of the second diagonal?

• Zero

• Positive 4

• Negative 3

• Positive 3

What is the sum of the products of the upward diagonals?

• 1

• 2

• 3

• 4

Which corner do you start from when calculating the upward diagonals?

• Upper left

• Upper right

• Bottom left

• Bottom right

What operation is performed on the sums of the diagonal products to find the determinant?

• Addition

• Division

• Multiplication

• Subtraction

What is the final determinant of the matrix?

• 3

• 0

• 1

• 2

Tags

CCSS.7.NS.A.3

What is the result of subtracting the sum of the upward diagonals from the downward diagonals?

• 3

• 2

• 1

• 0

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CCSS.7.NS.A.3