Question

Which of the following are situations that can be modeled with a quadratic function? Select all that apply.

1)A tree decays 10% every six weeks
2)The height of a ball rolling down a hill
3)A gym charges $15 per fitness class
4)An antibiotic eliminates 50% of bacteria every 24 hours
5)The height of a rocket after it is launched

Answer 1

4 antibiotic eliminates because it’s something that helps and it a quadratic function

Answer 2

5) The height of a rocket after it is launched
For this case, what you should do is remember the kinematics expressions where we have:
a
v = a * t + vo
y = a * t ^ 2 + vo * t + i
Where,
a: acceleration
v: speed
y: vertical position
t: time
vo: initial speed
yo: initial position
We observe that the expression for the given position is given by a quadratic expression.