Transcript of DETERMINANTS AND INVERSE MATRICES. I. Determinants of 2x2 A. Formula.
DETERMINANTS AND INVERSE MATRICES
I. Determinants of 2x2
A. Formula
I. Determinants of 2x2
B. Examples. Find the determinant.
Ex 1.
Ex 2. Ex 3.
Remark: Matrix with determinant 0 is called singular.
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II. Determinants of 3x3
A.Steps1.Rewrite columns 1 and 2 to the right of column 3.2.Multiply down-diagonals and add them together.3.Multiply up-diagonals and add them together.4.Subtract: down-diagonals – up-diagonals
II. Determinants of 3x3
B.Examples. Find the determinant.
Ex 1.
II. Determinants of 3x3
B.Examples. Find the determinant.
Ex 2.
II. Determinants of 3x3
B.Examples. Find the determinant.
Ex 3.
III.Inverse MatricesRemark: A matrix has an inverse if and only if .