



 
Hi Megan, Draw a coordinate system on the plane with the xaxis at ground level and the yaxis the axis of symmetry of the parabola. The width of the bridge is 192 feet so the parabola crosses the xaxis with xcoordinates ± 192/2 = ± 96. The maximum height occurs at x = 0 so the vertex of the parabola is (0, 30). Since the curve is a parabola which opens downward its equation can be written f(x) = ax^{2} + bx + c.
I hope this helps,  


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