Jamie kicked a soccer ball that traveled along a path described by the parabola y = -x^2 +8x, where y equals the height of the soccer ball in feet, and x = the horizontal distance in feet that the ball has traveled from Jamie.  How many feet from Jamie does the soccer ball hit the ground?

Respuesta :

the answer is 8 feet

Equation of any Parabola is of the form y= [tex]ax^{2}+bx+c[/tex]

If a is negative the parabola opens down.

The given equation of  soccer ball that traveled along a path was y=[tex]-x^{2}+8x[/tex]

Comparing the two equations we have a=-1,b=8

As a is negative the parabola opens down and will have the maximum point at  vertex .

The x of vertex is given by x=[tex]\frac{-b}{2a}[/tex]

Substituting a and b values we have:

x=[tex]-\frac{-8}{2x1} =\frac{8}{2}= 4.[/tex]

The y of vertex is y=[tex](-4)^{2}+8(4) =16[/tex]

The highest point the soccer ball hit the ground is 16 ft.