Answer:
see the explanation
Step-by-step explanation:
we have the quadratic equation
This is a vertical parabola open downward
The vertex is a maximum
Find the x-intercepts of the quadratic equation
The x-intercepts are the values of x when the value of y is equal to zero
so
For y=0
Solve the quadratic equation
The formula to solve a quadratic equation of the form
is equal to
in this problem we have
so
substitute in the formula
therefore
This parabola has two x-intercepts representing the times when the dolphin's height above water is zero feet