Day 126 Practice
Name _________________________________
Decide whether the graph of the equation opens up or down. Then find the coordinates of the
vertex.
1) 𝑦 = 3𝑥 2
4) 𝑦 = 𝑥 2 + 6𝑥
2) 𝑦 + 2𝑥 2 = 0
5) 𝑦 − 8 = −3𝑥 2
3) 𝑦 = 5𝑥 2 − 1
6) 𝑦 = −2𝑥 2 − 8𝑥
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Day 126 Practice
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7) 𝑦 = 𝑥 2 + 6𝑥 + 2
10) 𝑦 = −2𝑥 2 + 4𝑥 − 1
8) 𝑦 = 2𝑥 2 − 4𝑥 + 3
11) 𝑦 − 𝑥 2 = 2𝑥 + 4
9) 𝑦 = 3𝑥 2 − 12𝑥 − 2
12) 𝑦 + 3 = −𝑥 2 + 4𝑥
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Day 126 Practice
Name _________________________________
Sketch the graph of equation. Label the vertex.
13) 𝑦 = −𝑥 2 − 4
16) 𝑦 = 𝑥 2 + 2𝑥 − 15
14) 𝑦 = 𝑥 2 + 6𝑥 + 5
17) 𝑦 = 2𝑥 2 − 𝑥 − 1
15) 𝑦 = −𝑥 2 − 4𝑥 − 3
18) 𝑦 = 𝑥 2 − 6𝑥 + 10
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Day 126 Practice
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19) 𝑦 = −2𝑥 2 − 8𝑥 + 20
22) 𝑦 = − 3 𝑥 2 + 4𝑥 − 7
1
20) 𝑦 = 2𝑥 2 − 6𝑥 + 4
23) 𝑦 = 2 𝑥 2 + 2𝑥 − 1
21) 𝑦 = −𝑥 2 + 2𝑥 + 5
24) 𝑦 = 2𝑥 2 − 2 𝑥 + 1
1
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Day 126 Practice
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25) Gateway Arch. The Gateway Arch in St. Louis, Missouri, has a shape similar to that of a
parabola. The edge of the arch can be modeled by
2 2 92
880
ℎ=−
𝑥 + 𝑥−
315
91
7
where x and h are measured in feet. How high is the arch?
26) Valley depth. A model for a valley between two mountains whose peaks touch the 𝑥 = 𝑎𝑥𝑖𝑠
is 𝑦 = 40.4𝑥 2 − 404𝑥, where x and y are measured in feet. How deep is the valley?
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Day 126 Practice
Name _________________________________
Throwing a ball. In 27 and 28, use the following information.
1
The path of a ball thrown into the air from a height of 3 feet is given by 𝑦 = − 8 𝑥 2 + 𝑥 + 3,
where 𝑦 is the height of the ball in feet at a horizontal distance of 𝑥 feet from the thrower.
27) How high is the ball at its maximum height?
28) make a table and estimate the horizontal distance the ball travels before hitting the ground.
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Day 126 Practice
Name _________________________________
Swish. In 29 and 30, use the following information.
In the diagram below, the backboard is located on the y-axis and the hoop is located at the
point (1, 10). A basketball thrown toward the hoop follows the path 𝑦 = −0.36𝑥 2 + 2.8𝑥 +
7.56 where x and y are measured in feet.
29) When the ball was at its highest point, what was its horizontal distance from the
backboard?
30) At its highest point, how far off the ground was the basketball?
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Day 126 Practice
Answer Key
1. Up, (0, 0)
2. Down, (0, 0)
3. Up, (0, -1)
4. Up, (-3, -9)
5. Down, (0, 8)
6. Down, (-2, 8)
7. Up, (-3, -7)
8. Up, (1, 1)
9. Up, (2, -14)
10. Down, (1, 1)
11. Up, (-1, 3)
12. Down, (2, 1)
13.
Name _________________________________
15.
16.
14.
17.
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Day 126 Practice
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18.
21.
19.
22.
20.
23.
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Day 126 Practice
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24.
25. 630 ft.
26. 1010 ft.
27. 5 ft.
28. ≈ 10.3 ft.
29. ≈ 3.89 ft.
30. ≈ 13.00 ft.
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