Algebra 1 Common Core Student Edition, Grade 8-9

Pr act i ce an d Pr o b l em - So l v i n g Ex er ci ses

1 ^ 1 P ra c tic e

MATHEMATICAL

PRACTICES

Identify the vertex of each parabola. Tell whether it is a minimum or a maximum,

9.

4jd See Problem 1.

BD

0

Graph each function. Then identify the domain and range of the function. See Problem 2.

10. y = —4x2


11. fix) = |x2
    11. fix) = 1.5x2
    14. y — ~\x2
    12. fix) = 3x2
    15. y=-\x2

Order each group of quadratic functions from widest to narrowest graph.

16. y = 3x , y = 2x , y = 4x2


17. y = -\ x2, y = 5x2, y = - | x 2

Graph each function.

20. fix) = x2 + 4


21. fix) = -x 2 - 3
    17. fix) = 5x ,/(x) =
    19. fix) = —2x2,fix)

See Problem 3.

-3 x2,/(x) = x2

• 3x ,/(x) = — 4x

See Problem 4.

21. 
    

    y = x2 — 7

    
    


22. 
    

    y = —2x2 + 4

    
    


23. 
    

    y = |x2 + 2

    
    


24. 
    

    fix) = 4x2 - 5

    
    


25. 
    

    Dropped Object A person walking across a bridge accidentally drops an
    orange into the river below from a height of 40 ft. The function h = —16?2 + 40
    gives the orange's approximate height h above the water, in feet, after t seconds.
    Graph the function. In how many seconds will the orange hit the water?

    
    


26. 
    

    Nature A bird drops a stick to the ground from a height of 80 ft. The function
    h = —1612 + 80 gives the stick's approximate height h above the ground, in feet,
    after t seconds. Graph the function. At about what time does the stick hit the
    ground?

    
    

See Problem 5.

Q A p p ly © 2 8. E rro r A n alysis Describe and correct the error

made in graphing the function y : - 2 x + 1.

Identify the domain and range of each function.

29. fix) = 3x2 + 6 30. y = -2x 2 - 1


30. y =--x24X 32. y = |x2 + 12

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\y

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33. W riting What information do the numbers a and c
    give you about the graph of y = ax2 + c?

550 Ch ap t er 9 Quadratic Functions and Equations