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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

Thanks for the points ! :)