1. Do Now 3/20/19
Take out HW from last night.
Text p. 436, #4-26 evens, 29
Copy HW in your planner.
Practice worksheet 8.3
Quiz sections Friday, 3/22
In your notebook, answer the following. The function y = -16t represents the height y (in feet) of egg being dropped t seconds from a building.
a. After how many seconds does egg hit the ground?
b. A second egg is dropped from a height of 100 feet. Which egg hits the ground in the least amount of time? What is the difference in time of the faster egg? Explain.

2. Second drop: t = 2.5 seconds.
Difference is 0.5 seconds.

3. Homework Text p. 436, #4-26 evens, 29

4. Homework Text p. 436, #4-26 evens, 29

5. Homework Text p. 436, #4-26 evens, 29

6. Learning Goal Learning Target SWBAT graph quadratic functions
SWBAT practice graphing functions of the form f(x) = ax² + bx + c

7. Section 8.3 “Graph f(x) = ax² + bx + c”
Properties of the Graph of a Quadratic Function
y = ax² + bx + c is a parabola that:
-opens up if a > 0
-opens down if a < 0
-is narrower than y = x² if the |a| > 1
-is wider than y = x² if the |a| < 1
-has an axis of x = -(b/2a)
-has a vertex with an x-coordinate of -(b/2a)
-has a y-intercept of c. So the point (0,c) is on the parabola

8. Finding the Axis of Symmetry and the Vertex of a Parabola
Consider the graph y = -2x² + 12x – 7
(a) Find the axis of symmetry of the graph
(b) Find the vertex of the graph
Axis of symmetry:
Substitute
a = -2
b = 12
Substitute the x-value into the original equation and solve for y.
The vertex of the parabola
is the point (3,11)

9. Graph y = 3x² - 6x + 2 Step 1: Determine if parabola opens up or down
Step 2: Find and draw the
axis of symmetry
Step 3: Find and plot the vertex
Step 4: Plot two points. Choose two x-values less than the x-coordinate of the vertex. Then find the corresponding y-values. x y 2 -1 11
Step 5: Reflect the points plotted over the axis of symmetry.
Step 6: Draw a parabola through the plotted points.
Minimum Value

10. Graph y = -1/4x² - x + 1 Step 1: Determine if parabola
opens up or down
DOWN
Step 2: Find and draw the
axis of symmetry
Step 3: Find and plot the vertex
Step 4: Plot two points. Choose two x-values more than the x-coordinate of the vertex. Then find the corresponding y-values. x y 1 2 -2
Step 5: Reflect the points plotted over the axis of symmetry.
Maximum Value
Step 6: Draw a parabola through the plotted points.

11. Minimum and Maximum Values
For y = ax² + bx + c, the y-coordinate of the vertex is the MINIMUM VALUE of the function if a > 0 or the MAXIMUM VALUE of the function if a < 0.
y = ax² + bx + c; a > 0
y = -ax² + bx + c; a < 0
maximum
minimum

12. Real-Life

13. A group of friends is launching water balloons
A group of friends is launching water balloons. The function f(t) = -16t2 + 80t + 5 represents the height (in feet) of the first balloon t seconds after it is launched. The height of the second balloon t seconds after it is launched is shown in the graph. Which water balloon went higher?

14. A group of friends is launching water balloons
A group of friends is launching water balloons. The function f(t) = -16t2 + 80t + 5 represents the height (in feet) of the first balloon t seconds after it is launched. The height of the second balloon t seconds after it is launched is shown in the graph. Which water balloon went higher?

15. EARN A BADGE!!

16. Homework/Classwork
Practice worksheet 8.3