2. Date: 1.9(b) Notes: Using the Square Root Property Lesson Objective: Solve quadratics using factoring and the Square Root Property. CCSS: A.SSE.3a, A.REI.1 You will need: a calculator Real-World App: What are the solutions to the Justin Bieber fundraiser concert? This is Jeopardy!!!: These are the solutions to x² = 225.

3. Lesson 1: What are the Solutions to the Justin Bieber Concert Fundraiser? Recall that you are in charge of fundraising and booked Justin Bieber for a concert. The venue available is square in shape with sides of (4n + 1)ft. Justin requires a square stage with dimensions of 15 feet. What are the solutions to this equation?

4. Lesson 1: What are the Solutions to the Justin Bieber Concert? We came up with the expression: (4n + 1)² – 15 To make it an equation, set it equal to 0: (4n + 1)² – 15 = 0 And solve: What does it mean that these are the solutions?

5. Lesson 1: What are the Solutions to the Justin Bieber Concert? Solutions to an Equation: The value(s) of the variable when the equation = 0; AKA roots, zeros, and factors; the point(s) where the graph of the equation crosses the x-axis.

6. Lesson 2: Square Root Property Notice the +. That means there is a + solution and a – solution. Square Root Property: To solve x² = a, take the square root of both sides. x² = a √x² = √a x = + a

7. Lesson 2: Square Root Property Solve each equation. A.n² = 49 B.(a – 10)² = 121 C.4y² = 45

8. Lesson 3: Solving by Factoring. Set the equation = 0. Factor the equation. Solve each equation. A.a² + 12a = -36 B.9x² – 6x + 4 = 0

9. Lesson 4: Gravity at Work How long does it take something to fall to the ground? Let’s try dropping a ball 4 feet from the ground. We can use the following formula: h = -16t² + h 0 h = h 0 = t =

10. 1.9(b): Do I Get It? Yes or No Solve each equation. 1.(y – 6)² = 81 2.(x + 6)² = 12 3.9x² – 48x = -64 4.Find the time it takes a ball to reach the ground if it is dropped from a height of 205 feet. Use the formula h = -16t² + h 0 where h = ground height = 0.