math
posted by nisa on .
A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation y = 0.06x^2 + 9.6x + 5.4 where x is the horizontal distance, in meters from the starting point on the roof and y is the height in meters of the rocket above the ground how far horizontally from its starting point will the rocket land?/ round your answer to the nearest hundredth
4.30 m
160.56 m
160.23 m
13.94 m

find the zeros of that parabola, use the + one
(I turned the parabola upside down because I like positive x^2 term)
.06 x^2  9.6 x  5.4 = 0
use x = [b +/ sqrt(b^24ac) ]/2a
while I use wolfram alpha
http://www.wolframalpha.com/input/?i=+.06+x^2++9.6+x++5.4+%3D+0++
to get 160.56