The vertex can be found at x=0, i.e, h=290. The vertex tells us that the bridge is 290 ft. high at its' midpoint. The max width is when y=0, or, in other words: 0.0159x²=290 x²=290/.0159= 18239 x=±135.05 The distance between the feet of the arch is 2x135.05, or 270.10 ☺☺☺☺
