Question 1071189

You can model an arch at your school using the equation y=−0.9(x+3)(x−3)y=−0.9(x+3)(x−3), where xx and yy 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.
<pre>Based on the given equation, x + 3 = 0, and x - 3 = 0, so roots are: - 3, and 3. 
Distance from - 3 to 3 is: 3 - - 3, or 3 + 3, or {{{highlight_green(matrix(1,2, 6, feet))}}}.
That's it!!