SOLUTION: 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 gr

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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.
Found 2 solutions by josmiceli, MathTherapy:
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
The arch meets with the ground are the values of
where
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The distance between ( -3, 0 ) and ( 3, 0 )
is
The width of the arch at ground level is 6 ft
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Here's the plot of the equation:
Answer by MathTherapy(10555)   (Show Source): You can put this solution on YOUR website!

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.
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 .

That's it!! 

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