# Can someone help me and check these?

1. Graph the function and identify the domain and range.

y = –.5x² (1 point)graph

*domain: (–∞, ∞)
range: [0, ∞)
graph

domain: (–∞, ∞)
range: (–∞, 0]
graph

domain: (–∞, ∞)
range: (–∞, 0]
graph

domain: (–∞, ∞)
range: [0, ∞)

2. How is the graph of y = –2x² – 5 different from the graph of y = –2x²? (1 point)

It is shifted 5 units up.
It is shifted 5 units down.
*It is shifted 5 units left.
It is shifted 5 units right.

3. A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation
y = –0.04x2 + 8.3x + 4.3 , where x is the horizontal distance, in meters, from the starting point on the roof and y is the height, in meters, of the rocket above the ground. How far horizontally from its starting point will the rocket land? Round your answer to the nearest hundredth meter. (1 point)
*208.02 m
416.03 m
0.52 m
208.19 m

4. Landon is standing in a hole that is 6.5 m deep. He throws a rock, and it goes up into the air, out of the hole, and then lands on the ground above. The path of the rock can be modeled by the equation y =–0.05x² + 4.5x – 6.5, where x is the horizontal distance of the rock, in meters, from Landon and y is the height, in meters, of the rock above the ground. How far horizontally from Landon will the rock land? Round your answer to the nearest hundredth of a meter. (1 point)18.07 m
35.96 m
9.04 m
*71.93 m

5. How many real number solutions does the equation have?

y = –4x² + 7x – 8 (1 point)no solutions
*one solution
two solutions
infinitely many solutions

6. How many real number solutions does the equation have?

y = 3x² + 18x + 27 (1 point)one solution
two solutions
no solutions
*infinitely many solutions

7. Graph the set of points. Which model is most appropriate for the set?

(–6, –1), (–3, 2), (–1, 4), (2, 7) (1 point)graph a
*graph b
graph C
graph D

8. What type of equation will best fit the data below?

graph (1 point)linear
*exponential
There is no pattern; no model will fit the data well.

9. Find the solutions to the system.

y = x² – 5x + 2

y = –6x + 4 (1 point)(2, 8) and (−1, 2)
*(−2, 8) and (1, −2)
(−2, 16) and (1, −2)
no solutions

10. Find the solutions to the system.

y = x² – 3x – 1

y = 8x – 1 (1 point)
(0, −1) and (11, 388)
*(0, −1) and (11, 87)
(−1, 0) and (87,11)
no solutions

11. If an object is dropped from a height of 85 feet, the function h(t) = –16t² + 85 gives the height of the object after t seconds. Approximately, when will the object hit the ground? (1 point)85.00 seconds
69.00 seconds
0.33 seconds
*2.30 seconds

12. A ball is thrown into the air with an upward velocity of 32 feet per second. Its height, h, in feet after t seconds is given by the function h(t) = –16t² + 32t + 6. How long does it take the ball to reach its maximum height? What is the ball’s maximum height? Round to the nearest hundredth, if necessary. (1 point)Reaches a maximum height of 22 feet after 1.00 second.
*Reaches a maximum height of 22 feet after 2.00 seconds.
Reaches a maximum height of 44 feet after 2.17 seconds.
Reaches a maximum height of 11 feet after 2.17 seconds.

13. A catapult launches a boulder with an upward velocity of 148 ft/s. The height of the boulder (h) in feet after t seconds is given by the function h = –16t² + 148t + 30. How long does it take the boulder to reach its maximum height? What is the boulder’s maximum height? Round to the nearest hundredth, if necessary. (1 point)

*Reaches a maximum height of 30 feet after 9.25 second.
Reaches a maximum height of 640.5 feet after 4.63 seconds.
Reaches a maximum height of 1,056.75 feet after 4.63 seconds.
Reaches a maximum height of 372.25 feet after 4.63 seconds.

14. Use the graph of f (x) to find the solutions to the equation f (x) = 0.

graph (1 point)
two solutions: x = 6, –2
*two solutions: x = –6, 2
one solution: x = –12
no solutions

15. What are the solutions of the equation 2x² = 8? Use a graph of the related function. (1 point)graph

There are two solutions: –4 and 4.
B
*C
D

16. Solve the equation using the Zero Product Property.

(2x – 4)(2x – 1) = 0 (1 point)2, –1over2
2, 1over2
*–2, 2
–2, 1over2

17. What are the solutions of the equation?

0 = x² + 3x – 10 (1 point)
x = 5, 2
x = –5, –2
*x = –5, 2
x = 5, –2

18. A community group is planning the expansion of a square flower garden in a city park. If each side of the original garden is increased by 9 meters, the new total area of the garden will be 169 square meters. Find the length of each side of the original garden. (1 point)9 m
13 m
*2 m
4 m

19. What is the value of c so that y = x² + 9x + c is a perfect square trinomial? (1 point)18
nine over two
*nine over four
81 over 4

Solve the equation by completing the square. Round to the nearest hundredth if necessary.

20. x² + 10x = 18 (1 point)–11.56, 1.56
*11.56, 1.56
–11.56, –1.56
11.56, –1.56

21. Solve the equation by completing the square.

x² + 9x – 14 = 0 (1 point)10.35, 1.35
*10.35, –1.35
–10.35, –1.35
–10.35, 1.35

22. Use the quadratic formula to solve the equation. If necessary, round to the nearest hundredth.

x² – 21 = –4x (1 point)7, 3
–7, 3
*7, –3
–7, –3

23. Which kind of function best models the data in the table? Use differences or ratios.

table (1 point)linear
*exponential
none of the above

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1. #1:
range: (–∞, 0]
graph: parabola opening downward.
since x^2 is always positive, -.5x^2 is always negative

#2: It is shifted 5 units down.
take a look at
http://www.wolframalpha.com/input/?i=plot+y+%3D+-2x^2%2C+y%3D-2x^2-5

#3:ok

#4: I get 88.5 m. See
http://www.wolframalpha.com/input/?i=%E2%80%930.05x%C2%B2+%2B+4.5x+%E2%80%93+6.5

#5: no solutions
b^2-4ac is negative

#6: one solution
b^2-4ac = 0
No parabola can intersect the x-axis in infinitely many places! You have some serious reviewing to do.
Every nth-degree polynomial has at most n real solutions.

#7: no idea - no graph

#8: no idea - no data shown

#9: two solutions, but not rational. None of the given points is a solution.

#10: (−2, 16) and (1, −2)
Don't always pick the first answer which matches part of yours. And for heaven's sake, check your answer to make sure it fits!

#11: ok

#12:Reaches a maximum height of 22 feet after 1.00 second.
see
http://www.wolframalpha.com/input/?i=%E2%80%9316t%C2%B2+%2B+32t+%2B+6

parabola vertex is at x = -b/2a, not -b/a

#13:
Reaches a maximum height of 372.25 feet after 4.63 seconds.
see
http://www.wolframalpha.com/input/?i=%E2%80%9316t%C2%B2+%2B+148t+%2B+30

see above re vertex

#14: no idea - no graph shown

#15: +2 and -2
No idea whether that is C

#16: 2 and 1/2
why ever would you write 1 over 2 instead of just showing the fraction?

#17: ok

#18: 4 m
since 169=13^2, the sides will be 13m. So, they are now 13-9 = 4m

#19: (9/2)^2 = 81/4

20: –11.56, 1.56
surely you could see that +11.55 would not work. adding up all those positive numbers on the left would far exceed 18.

#21: –10.35, 1.35
y = x^2+9x-14
y = x^2 + 9x + 81/4 - 14 - 81/4
y = (x + 9/2)^2 - 137/4
so, y=0 when
x = -9/2 ±√137/2
= -4.5 ± 5.85

#22: –7, 3

#23: no idea - no table

Looks like some serious one-on-one help is in order here.

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2. Here is a better copy of 11:

11. If an object is dropped from a height of 85 feet, the function h(t) = –16t^2 + 85 gives the height of the object after t seconds. Approximately, when will the object hit the ground? (1 point)

85.00 seconds
69.00 seconds
0.33 seconds
2.30 seconds

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3. –16t^2 + 85

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4. – 16 t^2 + 85 (sorry for having to repost so many times)

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5. negative 16t to the second power plus 85. :)

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6. For 20 and 21 are the x values in both negative and the y values positive?

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7. –16t^2 + 85 = 0 when t = √85 / 4

for 20 and 21, can you not see the - signs or their absence?

as for y, the x values are the solution when y = zero!

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8. I can't! the formatting is odd.

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9. Would 21 be negative 10.35, and positive 1.35

Would 20 be negative 11.56 and positive 1.56

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10. Ah. I never thought that would be a problem. I copied/pasted from your posting.

yes, you are correct in your interpretation.

the perils of word processors which use em-dashes instead of ascii minus signs.

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11. Who knows

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12. Im confused

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14. Wow, 8 years since i've posted this and still waiting on answer cheat sheet. SMH

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15. Im bout to take the test and give yall the right answers when im done!! IM TAKING ONE FOR ThE TEAM!!! love yall! Also add my in\$tagram 2brazy4yu._

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