1. 4.5 Determinants and Cramer’s Rule

2. Objectives Evaluate a determinant of a 2 x 2 matrix. Use Cramer’s rule for linear equations.

3. What does a 2 x2 determinate look like? Matrix A Determinant

4. The math of a 2 x 2determinant A Determinant

5. Example 1 (2x2 determinant) A Determinant Answer : -5

6. Example 2 (2x2 determinant)

7. Example 2 ANSWER 10

8. Cramer’s Rule Used to solve linear equations. (x,y) It can get messy. Follow your notes carefully. Practice will make it seem not too bad.

9. A Look at 2 Linear Equations is Standard Form.

11. Use Substitution.

12. After Substitution

13. Evaluate each determinant D = 22 Dx = 0 Dy = -44

14. Cramer’s Rule says that……… AND So,…

15. …..finishing our problem. & D = 22Dx = 0 Dy = -44 (0, -2)