1

Match the graph to its equation.

y = x2 y = ­ 1/5x2 y = 3x2

2

RECAP:Standard Form of a Quadratic Equation:

Shape of the graph is called:

Line that divides a parabola is called:

Each parabola has a _________________ or _________________ point called the

____________________.

"a" tells us two things

1. If a is positive, then ___________. If a is negative, then _____________.

2. a tells the ________________ of the parabola.

3

HW Solutions p. 321 # 1 ­ 12, 17 ­ 20, 29 ­ 391. a=1,b=2,c=4

2. a=2,b=0,c=0

3. a=­1,b=­3,c=­9

4. a=­2,b=0,c=5

5. up; min

6. up; min

7. down, max

8. down, max

17. widest to narrowest: y = x2, y = 3x2, y = 7x2

18. widest to narrowest: y = 1/3x2, y = x2, y = 4x2

19. widest to narrowest: y = ­2/3x2, y =­2x2, y = ­4x2

20. widest to narrowest: y = ­1/4x2, y = ­1/2x2, y = 5x2

29. y = 2x2: narrower

30. y = ­x2: flip over x­axis

31. y = 1.5x2: narrower

32. y = 1/2x2: wider

34. D

35. E

36. B

37. F

38. A

39. C

4

9. y = 1/2x2

10. y = 1.5x2

5

11. y = ­4x2

12. y = ­1/3x2

6

7-2 Graphing Simple Quadratic Functions

Objective: Graph quadratic functions of the form y = ax2 + c.

7

Graph each function.

What is a, b, and c for each?

What is different about these three graphs?

y = x2

y = x2 + 2

y = x2 ­ 3

8

Conclusions about cIf c is positive the graph shifts ____________ from the x-axis.

If c is negative the graph shifts ___________ from the x-axis.

c is also the _______________ of the quadratic function.

9

What would be different about the graphs

y = 1/2x2 and y = 1/2x2 - 4 ?

10

Graph y = 2x2 + 1

opens ______

y­int ________

min or max______

11

Graph y = -x2 + 3

opens ______

y­int ________

min or max_____

12

y = -10x2 + 4.5

y = -3x2 + 4

y = -2x2 - 1

1. most narrow?

2. opens upward?

3. y-intercept is below x-axis?

4. widest?

5. maximum point?

13

BB # 3

Due 3/4HW # 69

p. 325-26 # 1-9,18,19,21-32

**Need graph paper for 6-9 !!