math
posted by lisa on .
The height in feet of a rocket after t seconds is given by h(t) = 160t  16t2.
Find the maximum height the rocket attains:
After how many seconds does it reach this height?

16x^2 + 160t
The max. point on the parabola is the vertex:
t = Xv = B/2A = 160/32 5 s
hmax. = Yv = 16*5^2 + 160*5 = 400 Ft.
V(5,400).