1. The problem statement, all variables and given/known data A bridge is to be constructed across a river that is 150 feet wide. The arch of the bridge is to be semi-elliptical and must be constructed so that a ship less than 50 feet wide and 40 feet high can pass safely through the arch, as shown in the figure. (a) Find an equation for the arch. (Let x be the independent variable and y be the dependent variable. Assume the origin is at the surface of the river directly beneath the highest point of the arch.) (b) Approximate the height of the arch in the middle of the bridge. (Round your answer to the nearest whole number.) 2. Relevant equations x2/a2 + y2/b2 = 1 3. The attempt at a solution I actually don't understand it. As far as I know, the 150 needs to halved, thus making it: x2/752 + y2/b2 = 1 But I'm stuck from there...can anyone help?