First one is correct. The second one should be "d". You can check these answers by putting them into the original equation. You should get zero for an answer because "O" is when it hits the ground.
For 5 & 6 use the square root of b^2 - 4ac. If you get a zero under the root, there is one solution, if you get a positive number there are two and if you get a negative number there are two imaginary solutions.
7) make an x-axis and y-axis and plot the points (x,y) is the correct order.
2x+2 = x^2+3x-4
0 = x^2 +x -6
0 = (x-2)(x+3)
x = 2 x = -3
now find y but substituting.
I don't agree with the answer you have above.
1) [I don’t need any help with this question.]
2) [I don’t need any help with this question.]
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=-0.04x^2+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.
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=-0.05x^2+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)
a. 82.03 m <----
b. 6.50 m
c. 90.00 m
d. 88.53 m
5) How many real number solutions does the equation have? (1 point)
0 = 5x^2 + 2x – 12
One solution
Two solutions
Infinitely many solutions
No solutions
6) How many real number solutions does the equation have? (1 point)
-8x^2 – 8x – 2 = 0
One solution
Two solutions
No solutions
Infinitely many solutions
7) Graph the set of points. (1 point)
(-6,4)(-4,0)(-3,-2)(-1,-7)
[I don't know the answer]
8) [I already know the answer to this one, so I don’t need help with this one.]
9) Find the solutions of the system.
y = x^2 + 3x - 4
y=2x + 2
(-3,6) and(2,-4)
(-3,-4) and (2,6)
(-3,-4) and (-2,-2) <----
No solution
10) Find the solutions to the system. (1 point)
y = x^2 + 8x + 2
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
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. What is the ball’s maximum height? How long does it
take the ball to reach its 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
3 answers
10) set the quadratic equal to zero and then use the quadratic equation to solve.
x = -b +- square root of (b^2-4ac)
all of that is divide by 2a
11) the height has to be zero when it hits the ground. Set the equation = 0 and use the quadratic to solve. However, since this is MC, you could just substitute in the answers to see if you will get zero.
x = -b +- square root of (b^2-4ac)
all of that is divide by 2a
11) the height has to be zero when it hits the ground. Set the equation = 0 and use the quadratic to solve. However, since this is MC, you could just substitute in the answers to see if you will get zero.
#12 recall that the vertex of a quadratic (max height in this case) occurs when
t = -b/2a = -32/-32 = 1
t = -b/2a = -32/-32 = 1