Answer:
The answer is below
Explanation:
The question is not complete, the complete question is:
A skydiver is 760 meters above the ground when he opens his parachute. After opening the parachute, he descends at a constant speed of 17 meters per second.
a) A function gives a relationship between two variables (an independent and dependent variable). The dependent variable is dependent on other variables (output) while the independent variable is not dependent on other variables (input).
Let x be the number of seconds after the parachute is opened and y be the height of the parachute above the ground. Hence the equation that models the situation is:
y = 760 - 17x
At a height of 400 m, the number of seconds is:
y = 760 - 17x
400 = 760 - 17x
17x = 760 - 400
17x = 360
x = 21.2
x ≅ 21 seconds
It takes 21 seconds to reach a height of 400 m
b) Domain is the set of all independent variables. In this case the independent variable is the time (x)
The minimum time is at y = 760
y= 760 - 17x
760 = 760 - 17x
17x = 0
x = 0
The maximum time is at y = 0
y= 760 - 17x
0 = 760 - 17x
17x = 760
x = 44.7
Hence the domain = 0 ≤ x ≤ 44.7