1. Objective: 1d Textbooks pages: 199 – 210 Units: 4.5, 4.6

2. Objective: 1d  Teacher will ensure students can evaluate determinants of 2 x 2 and 3 x 3 matrices; find inverse matrices; use inverse matrices to solve matrix equations; make real-world connections with respect to matrices.  Students will be able too evaluate 2 x 2 and 3 x 3 matrices; find the determinants of each matrices type; evaluate inverse matrices and make real- world connections using matrices.

3. Multiplicative Inverse Will have the following solution: 10 0 1 0 0 0 1 10 0 1 Diagonal “1”

4. Matrices are Multiplicative Inverse? 21 2.5 1 -2 2 5 -4 2 1 -2 5 (2)(-2) + (1)(5) = 1 1 (2)(2) + (1)(-4) = 0 2 -4 0 (2.5)(-2) + (1)(5) = 0 2.5 1 0 (2.5)(2) + (1)(-4) = 1 1 YES

5. Matrices are Multiplicative Inverses? -5 7 -2 3 -3 7 -2 5

6. Multiplicative Inverse? 1/5 -1/10 0 1/4 52 0 4

7. misconception Students want to set the products ad and bc equal to each other as is done when solving proportions. Emphasize they should find the difference of the products when evaluating a determinant. D ifference D eterminant

8. Determinant of Matrices a b c d ad - bc -3 4 2 -5 (-3)(-5) – (4)(2) = 7

9. Matrix Determinant 62 -6 -2 -2 0 2 -1

10. 3 x 3 -3 4 0 2 -5 1 0 2 3 2 nd X --> EDIT 3 x 3 enter values 2 nd X --> math #1 2 nd X #1

11. Your turn 1 -1 2 0 4 2 3 -6 10 22

12. Inverse + Calculator 20 -1 -1 -1 1 3 2 0 0.4 0.4 0.2 -0.6 -0.6 0.2 -0.2 0.8 0.4 MODE (quit) 2 nd X #1 X

13. You try… find Inverse -2 1 -1 2 0 4 0 2 5 -4 -3.5 2 -5 -5 3 2 2 -1