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Try both problems on your own…
Vocabulary: identity matrix, inverse matrix identity matrix, inverse matrix Objectives: 1. Find the identity matrices 2. Find 2x2 inverse matrices 3. Find an inverse matrix using a calculator 4. Use inverse matrices to solve matrix equations
5 + 0 = 5 because 0 is the additive identity 4 x 1 = 4 because 1 is the multiplicative identity Therefore, A x ? = A, ? will be the identity matrix. Dependent on the dimensions of A. If you need a 2x2 matrix If you need a 3x3 matrix
= 0 because -5 is the additive inverse that gives the additive identity 2 x ½ = 1 because 1 is the multiplicative inverse that gives multiplicative identity Therefore, A x ? = I because ? is the inverse matrix that gives the identity matrix. What is the inverse matrix?
The inverse of matrix: Find the inverse of a square matrix: 1.Find the determinant of A 2.Switch the down and negate the up Determinant of A ≠ 0!
The inverse of matrix: Find the inverse of a square matrix: 1.Find the determinant of A 2.Switch the down and negate the up Determinant of A ≠ 0!
The inverse of matrix: Find the inverse of a square matrix: 1.Find the determinant of A 2.Switch the down and negate the up Determinant of A ≠ 0!
The inverse of matrix: Find the inverse of a matrix: 1.Input the matrix 2.On main screen, type matrix name with x -1 (inverse key) 3.Convert to fractions if desired
The inverse of matrix: Find the inverse of a matrix: 1.Input the matrix 2.On main screen, type matrix name with x -1 (inverse key) 3.Convert to fractions if desired
The inverse of matrix: Find the inverse of a matrix: 1.Input the matrix 2.On main screen, type matrix name with x -1 (inverse key) 3.Convert to fractions if desired
Why use inverse matrices? To solve equations! AX = B, solve for the mystery matrix X
Why use inverse matrices? To solve equations! AX = B, solve for the mystery matrix X
Why use inverse matrices? To solve equations! AX = B, solve for the mystery matrix X
Homework: pg. 227 #16, 18, 19, 25, 26, 29 pg. 227 #16, 18, 19, 25, 26, 29 CHAPTER 4 TEST ON THURSDAY, NOVEMBER 8 th ! CHAPTER 4 TEST ON THURSDAY, NOVEMBER 8 th !