Find the vertex of the parabola.

f(x) = -4x^2+40x-93

f(x) = (a)x^2 + (b)x +(c)

vertex's x value can be found by

-b/(2a)

b=40
a=-4
c=-93
-40/(2*-4)= 5
x=5
plug 5 in to get f(5)
(5,f(5))

This post was edited by saber_x3 on Apr 29 2013 01:10am