Respuesta :
The given function f(x)=-15x²+6000 represent a parabola or a quadratic equation.
Where x= time (in seconds) and f(x)= height (in feet).
Domain is the set of values of x at which the function must be defined. But there is no restriction for a quadratic function because it can take any value of x. Hence, domain of all quadratic functions or parabola are always
-∞≤x≤∞ or all real numbers.
So, domain of given function is " all real values of x".