You live near a bridge that goes over a river. The underside of the bridge is an arch that can be modeled with the function y = –0.000471x² + .837x where x and y are measured in feet. How high above the river is the bridge (the top of the arch)? How long is the section of bridge above the arch?
The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 888.54 ft.
The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 1,777.07 ft.
The bridge is about 371.85 ft. above the river, and the length of the bri

Question

You live near a bridge that goes over a river. The underside of the bridge is an arch that can be modeled with the function y = –0.000471x² + .837x where x and y are measured in feet. How high above the river is the bridge (the top of the arch)? How long is the section of bridge above the arch?
The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 888.54 ft.
The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 1,777.07 ft.
The bridge is about 371.85 ft. above the river, and the length of the bri

anonymous · Answer

The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 888.54 ft.
The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 1,777.07 ft.
The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 888.54 ft.
The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 371.85 ft.

anonymous · Answer

plss help???

campbell_st · Answer

ok... to find the distance spanned by the arch you need to solve it

so 

$$-0.00047x^2 + 0.837x = 0... or... -x(0.00047x - 0.837)$$

so 

x = 0 or 0.837/0.00047

the distance between the points will be the distance spanned. 

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