Problem page
a ball is thrown vertically upward. after t seconds, its height h (in feet) is given by the function h(t) = 120t - 16t^2 . after how long will it reach its maximum height?
do not round your answer.

 After 3.75 seconds

Step-by-step explanation:

 For a Quadratic function in the form , if then the parabola opens downward.

Rewriting the given function as:

You can identify that

Since the the parabola opens downward.

Therefore, we can conclude that the x-coordinate of the vertex is the time in seconds in which the ball will reach the maximum height. You can  find it with this formula:

Substitute values, we get

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.

the functions have the same rate of change i think. i narrowed it down to this answer and "the rate of change of tour 1 is greater" but i got it wrong using that answer so im assuming its the answer above. (this is a question i also answered from the iready site if anyone needs a reference)