1. Martin-Gay, Developmental Mathematics 1 Warm-Up #28 (Thursday, 11/12)

2. Martin-Gay, Developmental Mathematics 2 Homework (Thursday, 11/12) Lesson 3.02 worksheet

3. Lesson 3.02 The Quadratic Formula

4. Martin-Gay, Developmental Mathematics 4 The Quadratic Formula Another technique for solving quadratic equations is to use the quadratic formula. The formula is derived from completing the square of a general quadratic equation.

5. Martin-Gay, Developmental Mathematics 5 A quadratic equation written in standard form, ax 2 + bx + c = 0, has the solutions. The Quadratic Formula

6. Martin-Gay, Developmental Mathematics 6 Solve 11n 2 – 9n = 1 by the quadratic formula. 11n 2 – 9n – 1 = 0, so a = 11, b = -9, c = -1 The Quadratic Formula Example

7. Martin-Gay, Developmental Mathematics 7 x 2 + 8x – 20 = 0 (multiply both sides by 8) a = 1, b = 8, c =  20 Solve x 2 + x – = 0 by the quadratic formula. The Quadratic Formula Example

8. Martin-Gay, Developmental Mathematics 8 Solve x(x + 6) =  30 by the quadratic formula. x 2 + 6x + 30 = 0 a = 1, b = 6, c = 30 So there is no real solution. The Quadratic Formula Example