Answer:
Step-by-step explanation:
First off, we are given a parabola by definition:
Since , our parabola has an upward opening.
Should we think about it graphically, it will be no wonder that we should pay our attention to the points of the parabola intersecting the abscissa axis. In other words, we need our vertex to intersect the x axis only once per se.
The vertex:
As a result, our is parametric. suits us because . If , we do not have any roots at all. We have two roots if .
V=d/t
=> v=120/
()
v=120/
v=120*4/7
v=480/7 mph
The problem must have an error because the answer is 480/7 and not 7/480 mph.
15% of 68 = 10.2
68 - 10.2 = 57.8
68 decreased by 15% is 57.8