The function y=-0.2x^2+1.9x models the path of a kicked soccer ball.The height is y,the distance is x, and the units are meters.How high does the soccer ball go?

Respuesta :

Answer:

The highest height the ball achieves is 4.5125 meters.

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}, y_{v})[/tex]

In which

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

[tex]y_{v} = -\frac{\Delta}{4a}[/tex]

Where

[tex]\Delta = b^2-4ac[/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]y_{v}[/tex].

In this question:

Quadratic function [tex]y = -0.2x^2 + 1.9x[/tex], which has [tex]a = -0.2, b = 1.9[/tex].

The maximum height of the ball is [tex]y_{v}[/tex].

Then

[tex]\Delta = b^2-4ac = (1.9)^2 - 4*(-0.2)(0) = 3.61[/tex]

[tex]y_{v} = -\frac{3.61}{4(-0.2)} = 4.5125[/tex]

The highest height the ball achieves is 4.5125 meters.