A parabolic bridge is 70 m wide. At a horizontal distance of 10 m in from the base of the bridge, the height of the bridge is 38 m. If the height at a point on the bridge is 54 m, at what
horizontal distance in from the base does this occur?
13. The Diver Time company makes digital watches for scuba divers. The company models its
price with the demand function p(x) = x + 31 and its costs with the function C(x) = 4x2 + 8x + 7.