Respuesta :
A. When the key reaches the ground, h = 0.
0 = -16t^2 + 64
16t^2 = 64
t^2 = 4
t = 2 seconds.
B. The reasonable domain of the function is [0, 2], since the function does not hold when the key reaches the ground. The range of the function is [0, 64] which corresponds to the domain.
0 = -16t^2 + 64
16t^2 = 64
t^2 = 4
t = 2 seconds.
B. The reasonable domain of the function is [0, 2], since the function does not hold when the key reaches the ground. The range of the function is [0, 64] which corresponds to the domain.
Answer:
It would take 2 seconds to the key to reach the ground.
The domain the function is: 0≤t≤2 or in interval notation [0,2].
The range of the function is: 0≤h≤64 or in interval notation [0,64].
Step-by-step explanation:
The provided function is: [tex]h=-16t^2 +64[/tex]
Where h represents the height and t represents the time.
Part(A) how long does it take the key to reach the ground?
When key will be at ground, the height will be 0.
Substitute the value of h=0 in above equation and solve for t.
[tex]-16t^2 +64=0[/tex]
[tex]-16(t^2 -4)=0[/tex]
[tex](t^2 -2^2)=0[/tex]
[tex](t+2)(t-2)=0[/tex]
[tex]t+2=0\ or\ t-2=0[/tex]
[tex]t=-2\ or\ t=2[/tex]
Ignore the negative value of t.
Hence, it would take 2 seconds to the key to reach the ground.
Part (B) what are the reasonable domain and range for the function h?
Time and Distance should be a positive number.
Thus, the value of t and h should be greater or equal to 0.
From the part (a) we know that the after 2 second the key will hit the ground so the value of t can be greater or equal to 0 but should be less or equal to 2.
Thus, the domain the function is: 0≤t≤2 or in interval notation [0,2].
The maximum height of the key will be at t=0.
Thus the maximum value of h can be 64 and minimum value can be 0.
The range of the function is: 0≤h≤64 or in interval notation [0,64].
