Question

You can model an arch at your school using the equation y=−0.8(x−5)(x+5), where x and y are measured in feet. The x-axis represents the ground. Find the width of the arch at ground level.
The width of the arch at ground level is ___ feet.

Answer 1

Answer:

10 ft

Step-by-step explanation:

At ground level, y = 0.  Setting −0.8(x−5)(x+5) = to 0, we get x = 5 and x = -5 as solutions.  The arch touchs the ground at x = -5 and x = 5 ft.

The width of the arch at ground level is 5 - (-5), or 10 ft.