Answer:
Option C. −4≤t≤−3
Step-by-step explanation:
we have
This is the equation of a vertical parabola written in vertex form
The parabola open upward (the leading coefficient is positive)
The vertex is a minimum
The vertex is the point (-3,5)
The function is increasing in the interval [-3,∞)
The function is decreasing in the interval (-∞,-3]
The function will have a negative average rate when the function will be decreasing
therefore
the answer is option C
Answer:
Distance from the airport = 894.43 km
Step-by-step explanation:
Displacement and Velocity
The velocity of an object assumed as constant in time can be computed as
Where is the displacement. Both the velocity and displacement are vectors. The displacement can be computed from the above relation as
The plane goes at 400 Km/h on a course of 120° for 2 hours. We can compute the components of the velocity as
The displacement of the plane in 2 hours is
Now the plane keeps the same speed but now its course is 210° for 1 hour. The components of the velocity are
The displacement in 1 hour is
The total displacement is the vector sum of both
The distance from the airport is the module of the displacement: