A projectile is shot into the air following the path, h(x) = -3x^2 + 30x + 300. At what time, value of x, will it reach a maximum height?
x = 1
x = 2
x = 4
x = 5

Respuesta :

Answer:

maximum at x=5

Step-by-step explanation:

This path is parabolic (represented by a parabola since it is given by a quadratic expression).The parabola has the branches down since its leading coefficient is negative (-3), so the maximum value of this function will correspond to the vertex of the parabola.

We can use the definition for the vertex of a parabola to find it.

For a general parabola of the form: [tex]y(x)=ax^2+bx+c[/tex],

the x-value of its vertex is given by the expression: [tex]x_{vertex} =-\frac{b}{2a}[/tex]

In our case, (since [tex]a[/tex]= -3,  and [tex]b[/tex]= 30) it becomes:

[tex]x_{vertex} =-\frac{30}{2*(-3)}=\frac{30}{6} =5[/tex]

Therefore, the projectile will reach its maximum at x=5