Answer:
Let take the center of bridge as our origin (0,0). Parabola having vertex at origin is represented by y=a.x^2
At the right far end or +ive x-axis side we've x=200 and y=75 , so a=75/(200^2)=0.001875
Y
Parabola equation y=0.001875*x^2
Height of cable from 100m from centre. Y=? ,X=100m
Y=0.001875*(100^2)
Y=18.75 m
Height of ropes at 100m from the center of bridge.
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