5.5 – The Quadratic formula

1. 5.5 – The Quadratic formula Objectives: Use the quadratic formula to find real roots of quadratic equations. Use the roots of a quadratic equation to locate the axis of symmetry of a parabola. Standard: 2.8.11.N. Solve quadratic equations.

4. a = -1 b = -3 c = 8 a = 4 b = 2 c = -3 a = 1 b = -6 c = 7 a = -4 b = -5 c = -5

5. QUADRATIC FORMULA: • If ax2+ bx + c = 0 and a ≠ 0, then the solutions, or roots, are

6. Use the quadratic formula to find the roots. Give exact solutions & approximate solutions to the nearest tenth.

7. Example 1a. x2 – 7x + 6 = 0 a = 1, b = -7, c = 6 or or

8. Example 1b 4x2 = 8 – 3x 0 = -4x2 + 8 – 3x a = -4, b = -3, c = 8 or

9. Example 1c 2x2 – 6x = -3 2x2 – 6x + 3 = 0 a = 2, b = -6, c = 3

10. Example 2 After watching a home-improvement show, the Wilkersons decided to build a patio along two sides of their home. Find the width of the patio if there is enough material to cover a surface area of 650 square feet. Nonsense

13. Example 4a

14. Example 4b

15. Example 4c

16. Example 4d

18. Homework Packet section 5.5