通过建立二次函数模型可解决现实生活中与桥相关的某些实际问题.例1如图1,宜昌西陵长江大桥属于抛物线形悬索桥,桥面(视为水平的)与主悬钢索之间用垂直钢拉索连接.桥两端主塔塔顸的海拔高 By establishing a quadratic function model, we can solve practical problems related to bridges in real life. Example 1 As shown in Figure 1, the Yiling Xiling Yangtze River Bridge is a parabolic suspension bridge with a bridge surface (regarded as horizontal) and a main suspension cable. Connected with vertical steel cables. The height of the main tower tower at both ends of the bridge is high.