1. David threw a baseball into the air
David threw a baseball into the air. The function of the height of the baseball in feet is ℎ=80𝑡−16 𝑡 2 , where t represents the time in seconds after the ball was thrown. How long will it take for the ball to fall back to the ground?
Problem of the Day

2. Section 4-3a Factor Quadratic Equations

3. Then
Now
Objectives
You found the greatest common factors of sets of numbers.
Write quadratic equations in standard form.
Factor quadratic equations.

4. Common Core State Standards
Content Standards
A.SSE.2 – Use the structure of an expression to identify ways to rewrite it.
F.IF.8.a – Use the process of factoring and completing the square in a quadratic function to show zeros, extreme values, and symmetry of the graph, and interpret these in terms of context.
Mathematical Practices
2) Reason abstractly and quantitatively.
Common Core State Standards

5. The factored form of a quadratic equation is: 0=𝑎 𝑥−𝑝 (𝑥−𝑞)
The factored form of a quadratic equation is: 0=𝑎 𝑥−𝑝 (𝑥−𝑞). In the equation p and q represent the x-intercepts of the graph of the equation. EXAMPLE:
Vocabulary

6. Write a quadratic equation in standard form with 3 4 and -5 as its roots.
Example 1

7. Write a quadratic equation in standard form with 1 2 and -5 as its roots.
Example 1

8. Factor the equation: 𝑥 2 −11𝑥+30=0
Example 4

9. Factor the equation: 𝑥 2 −4𝑥−21=0
Example 4

10. Factor the equations: 𝑥 2 −2𝑥=15 𝑥 2 +12𝑥=−36 𝑥 2 =2𝑥+99
Example 4

11. p.242 #1, 6, 14, 18, 19, 26, 27, 38, 39, 41 (Factor, do not solve!)
Homework