Originally Posted by **OverclockerR520**

4) One section of a suspension bridge has its weight uniformly distributed between two towers that are 400 feet apart and rise 90 feet above the horizontal roadway (see figure). A cable strung between the tops of the towers has the shape of a parabola, and its center point is 10 feet above the roadway. Suppose coordinate axes are introduced as shown in the figure.

a) Find the equation for the parabola.

b) Nine equally spaced vertical cables are used to support the bridge. Find the total length of these supports.