Answer:
1/3
Step-by-step explanation:
The average rate of change of a function f(x) on an interval [a, b] is given by the formula ...
rate of change = (f(b) -f(a))/(b -a)
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For the given function and interval, this is ...
(log₂(4·8) -log₂(4·2))/(8 -2) = (5 -3)/(6) = 1/3
The average rate of change is 1/3.
_____
In the attached graph, the line between the points at the ends of the interval can be seen to have a rise of 1 for a run of 3. Its slope is 1/3.
A stuntman jumping off a 20-m-high building is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film him between 15 m and 10 m above the ground. For which interval of time should the camera film him?
Answer:

Step-by-step explanation:
Given:
A stuntman jumping off a 20-m-high building is modeled by the equation
-----------(1)
A high-speed camera is ready to making film between 15 m and 10 m above the ground
when the stuntman is 15m above the ground.
height
Put height value in equation 1





We know that the time is always positive, therefore 
when the stuntman is 10m above the ground.
height
Put height value in equation 1







Therefore ,time interval of camera film him is 