EOCT Practice

Question of the Day

CCGPS GeometryDay 40 (10-2-13)

UNIT QUESTION: How are real life scenarios represented by quadratic functions?

Today’s Question:How do we graph quadratics in standard form?Standard: MCC9-12.F.IF.8

Coefficients2

0y ax bx ca

2

2

2

1. 5 24

2. 2 7 6

3. 9

y x x

y x x

y x

a, b, and c are coefficients

Examples:Find a, b, and c

Open Up / Open Down

2

0,0,

y ax bx cif a then parabola opens upif a then parabola opens down

A > 0

2 6y x x

Therefore, the parabolaopens up

Example #1

2 6y x x

A < 0Therefore, the parabolaopens down

Example #2

Examples:2

2

2

2

6. 3 2

7. 2 8

8. 3 4 1

9. 16

y x x

y x

y x x

y x

Determine if the Parabola Opens Up or Opens Down

Axis of SymmetryVertex Point

2bxa

1.Axis of symmetry is found using

2. To find the y coordinate of the vertexpoint, substitute x into the equationand solve for y.

Examples2

2

2

10. 4 9

11. 2 6

12. 6

y x x

y x x

y x x

Find the vertex point

y = a b cx x2

x b2a

y = a b cx x2

x -(x)2+2x-1 y (x, y)

2y 2 1x x

x b2a

Tell whether the graph opens up or down. Graph each using a T-chart. Find the axis of symmetry & vertex . Use a dotted line to graph the axis of symmetry.

x x2- 6x + 5 y (x, y)

1 6 52. y x x

x

b2a

x -(x)2- 2x+3 y (x, y)

2 2 32. y x x

x b2a

x (x)2 +2x-6 y (x, y)

23. y 2 6x x

x b2a

x (x)2+8x+13 y (x, y)

4 8 132. y x x

x b2a

x (x)2+8x+13 y (x, y)

25. y 2x x

x b2a

Homework

Practice Worksheet