quadratic functions

Question

A ball is dropped from the top of a building that is 1,000 feet high. Its height, in feet, as a function of the time, x, in seconds, after the ball was dropped, is given by the following equation, ƒ(x) = 1,000 - 16x ². Which set of numbers is appropriate as the domain for this function?

Answer 1

Hi Gerardo,

you asked Which set of numbers is appropriate as the domain for this function?

Apparently you forgot to write the set of suggested answers.

As you know f(x) is parabola and domain is all real number BUT in this case domain starts at zero until ball dropped on the ground.

Now. when ball dropped? the answer of this question is:

1,000 - 16x ²= 0

1000 = 16x^2

1000/16 = x^2

62.5 = x^2

7.90 = ± x-------> x = 7.90 acceptable SO DOMAIN IS (0, 7.9)

I hope it is useful,

Minoo