Question

A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation y=-0.8x^2 + 12x +25.8 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?
a. 25.80 m
b. 37.00 m
c. 17.24 m
d. 16.91 m

Answer 1

The rocket will land about 16.85 meters horizontally from the starting point. I would select choice D. I think you have a typo in your problem.

To find this answer, we need to find the point on the graph where this parabola hits the x-axis (or ground). 

Using the quadratic equation, we will get two answer about -1.85 and 16.85. The first value doesn't apply in the context of this story. The second answer would be the distance.