A soccer ball is punted in the air. Its height after x seconds can be modeled by a quadratic function. The soccer ball reaches its maximum height of 85 feet after 3 seconds. The ball is trapped at a height of 2.5 feet, 6 seconds after being kicked. Write a quadratic function that models the height of the soccer ball, x seconds after being kicked.

Respuesta :

Answer:

[tex]-9.31x^2+56.26x[/tex]

Step-by-step explanation:

Let the quadratic function be:

[tex]h=ax^2+bx+c[/tex]

Where [tex]h[/tex] is the height of soccer ball and

[tex]x[/tex] is the time in seconds.

Initially, at time [tex]x=0\Rightarrow h=0[/tex]

Therefore, [tex]c=0[/tex]

Given that,

[tex]x=3, h=85\\and\\x=6, h=2.5[/tex]

Putting the values and making equations in [tex]a,b[/tex] :

[tex]85=9a+3b\\2.5=36a+6b[/tex]

By solving the above equations, we get:

[tex]a=-9.31\\ and\\b =56.26[/tex]

So, the quadratic expression is:

[tex]-9.31x^2+56.26x[/tex]