Please help! I'm behind and need help. Only need help with these questions. Unit 4, Lesson 10 Math test (Quadratic Functions and Equations Unit Test). Thank you!
2. How is the graph of y equals -8x^2 - 2. different from the graph of y equals negative 8x squared.? (1 point)
It is shifted 2 units to the left
It is shifted 2 units to the right.
It is shifted 2 units up.
It is shifted 2 units down.
A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation y equals negative 0.06 x squared plus 9.6 x plus 5.4 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.
4.30 m
160.56 m
160.23 m
13.94 m
A physics student stands at the top of hill that has an elevation of 37 meters. He throws a rock and it goes up into the air and then falls back past him and lands on the ground below. The path of the rock can be modeled by the equation y equals negative 0.02 x squared plus 0.8 x plus 37 where x is the horizontal distance, in meters, from the starting point on the top of the hill and y is the height, in meters, of the rock above the ground.
How far horizontally from its starting point will the rock land? Round your answer to the nearest hundredth.
37.00 m
67.43 m
27.43 m
37.78 m
Find the solutions to the system.
y= x^2 - 5x + 2
y= -6x + 4
(2,8) and (-1, 2)
(-2, 8) and (1, -2)
(-2, 16) and (1, -2)
No solution
Find the solutions to the system
y=x^2-2x-2
y=4x+5
(-1, 1) and (7, -23)
(-1, 1) and (7, 33)
(-1, 33) and (7, 1)
No solution
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?
85.00 seconds
69.00 seconds
0.33 seconds
2.30 seconds
A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet after t seconds is given by the function h= -16t^2 + 28t + 7. 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.
Reaches a maximum height of 7 feet after 1.75 seconds.
Reaches a maximum height of 43.75 feet after 0.88 seconds.
Reaches a maximum height of 17.5 feet after 0.88 seconds.
Reaches a maximum height of 19.25 feet after 0.88 seconds.
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= -16t^2 + 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.
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.
What are the solutions of the equation?
0 = x^2 +3x - 10
x = 5, 2
x = negative 5, negative 2
x = negative 5, 2
x = 5, negative 2
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 3 meters, the new total area of the garden will be 225 square meters. Find the length of each side of the original garden.
15m
3 m
12 m
Square root of 12m
19. What is the value of c so that y = x^2 + 15x + c is a perfect square trinomial? (1 point)
30
15/2
15/4
225/4
Solve the equation by completing the square. Round to the nearest hundredth if necessary.
x^2 + 10x = 18
-11.56, 1.56
11.56, 1.56
-11.56, -1.56
11.56, -1.56
Solve the equation by completing the square.
x^2 + 9x - 14 = 0
10.35, 1.35
10.35, -1.35
-10.35, -1.35
-10.35, 1.35
4 answers
You don't for a minute expect somebody to actually do this test for you?
The rocket hits the ground when the height is zero. So, just solve
-0.06x^2+9.6x+5.4 = 0
The quadratic formula is probably best.
The rock problem is just the same, only with different numbers.
To solve
y= x^2 - 5x + 2
y= -6x + 4
just substitute the 2nd value for y into the 1st equation. Then you just have to solve
-6x+4 = x^2-5x+2
x^2+x-2 = 0
that should be no sweat.
The next one is just the same.
The dropped object is just another y=0 solution
For the maximum height problems, recall that the vertex (maximum value of)
ax^2+bx+c=0 occurs at x = -b/2a
x^2 +3x - 10 =0
(x+5)(x-2) = 0
...
or use the quadratic formula
For the garden, if the original side is x meters, then we have
(x+3)^2 = 225 = 15^2
so, x+3 = 15
#19 Recall that (x+a)^2 = x&2+2ax+a^2
You have
x^2 + 15x + c
so 15 = 2a
For completing the square, you do
x^2 + 10x = 18
Now, 2a=10, so a=5 and we have
x^2+10x+25 = 18+25
(x+5)^2 = 43
x+5 = ±√43
x = -5±√43
The other one is just the same idea.