S(t) = -16t^2+96t+256 the quadratic function models the balls height above the ground, s(t), in feet, t seconds after it was thrown when a person standing close to the edge on top of a 248-foot building throws a baseball ball vertically upward. When will the ball reach its maximum height, and what is the maximum height of the ball?

Respuesta :

Answer:

The ball reaches maximum height in 3 seconds.

The maximum height of the ball is of 400 feet.

Step-by-step explanation:

Vertex of a quadratic function:

Suppose we have a quadratic function in the following format:

[tex]f(x) = ax^{2} + bx + c[/tex]

It's vertex is the point [tex](x_{v}, f(x_{v})[/tex]

In which

[tex]x_{v} = -\frac{b}{2a}[/tex]

If a<0, the vertex is a maximum point, that is, the maximum value happens at [tex]x_{v}[/tex], and it's value is [tex]f(x_{v})[/tex]

In this question:

The height is modeled by:

[tex]s(t) = -16t^2 + 96t + 256[/tex]

So, the coefficients are:

[tex]a = -16, b = 96, c = 256[/tex]

Instant of time the ball reaches maximum height:

[tex]t_{v} = -\frac{96}{2(-16)} = -\frac{96}{-32} = 3[/tex]

The ball reaches maximum height in 3 seconds.

What is the maximum height of the ball?

This is s(3).

[tex]s(3) = -16t^2 + 96t + 256 = -16*3^2 + 96*3 + 256 = 400[/tex]

The maximum height of the ball is of 400 feet.