Inverse Matrices 3 x 3

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Inverse Matrices (3 x 3)

• How to find the inverse of a matrix

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The minor determinant
The minor determinant that corresponds to an
element is given by deleting the row and column
of the element.
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The minor determinant
The minor determinant that corresponds to an
element is given by deleting the row and column
of the element.
The minor determinant corresponding to the 5 is
11.
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The minor determinant
The minor determinant that corresponds to an
element is given by deleting the row and column
of the element.
The minor determinant corresponding to the -3 is
2.
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The minor determinant
The minor determinant that corresponds to an
element is given by deleting the row and column
of the element.
The minor determinant corresponding to the 8 is 7.
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Finding Inverses 3x3
An algorithm can be followed to find the inverse
of a 3x3 matrix, M.

• Find the matrix of minor determinants.
• Alter the signs of the minors which dont lie on
  the diagonals.
• Transpose
• Divide by det(M)

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Finding Inverses 3x3 (Example)
Make sure non-singular.

• Find the matrix of minor determinants.
• Alter the signs of the minors which dont lie on
  the diagonals.
• Transpose
• Divide by det(M)